Enzymes

@inproceedings{hartley1979evolution1,
    author = "Hartley, B. S",
    title = "Evolution of enzyme structure",
    year = "1979",
    booktitle = "Proceedings of the Royal Society, v. B205, p. 443-452",
    note = "talkorigins\_source = {true}; raw\_reference = {Hartley, B. S., 1979, Evolution of enzyme structure: Proceedings of the Royal Society, v. B205, p. 443-452.}"
}

@article{doi101002j146020751988tb03124x,
    author = "Mantei, Ned and Villa, Marco and Enzler, Thomas and Wacker, Hans and Boll, Werner and James, Anthony P. and Hunziker, Walter and Semenza, Giorgio",
    title = "Complete primary structure of human and rabbit lactase-phlorizin hydrolase: implications for biosynthesis, membrane anchoring and evolution of the enzyme.",
    year = "1988",
    journal = "The EMBO Journal",
    url = "https://doi.org/10.1002/j.1460-2075.1988.tb03124.x",
    doi = "10.1002/j.1460-2075.1988.tb03124.x",
    openalex = "W2110389243",
    references = "doi1010160003269783904189, doi1010160022283670900574, doi1010160022283685900464, doi1010160378111983900409, doi1010160378111983902305, doi101038263211a0, doi101073pnas612636, doi101073pnas74125463, doi101093nar121part1387, doi101093nar14114683"
}

The glutathione transferases are recognized as important catalysts in the biotransformation of xenobiotics, including drugs as well as environmental pollutants. Multiple forms exist, and numerous transferases from mammalian tissues, insects, and plants have been isolated and characterized. Enzymatic properties, reactions with antibodies, and structural characteristics have been used for classification of the glutathione transferases. The cytosolic mammalian enzymes could be grouped into three distinct classes--Alpha, Mu, and Pi; the microsomal glutathione transferase differs greatly from all the cytosolic enzymes. Members of each enzyme class have been identified in human, rat, and mouse tissues. Comparison of known primary structures of representatives of each class suggests a divergent evolution of the enzyme proteins from a common precursor. Products of oxidative metabolism such as organic hydroperoxides, epoxides, quinones, and activated alkenes are possible "natural" substrates for the glutathione transferases. Particularly noteworthy are 4-hydroxyalkenals, which are among the best substrates found. Homologous series of substrates give information about the properties of the corresponding binding site. The catalytic mechanism and the active-site topology have been probed also by use of chiral substrates. Steady-state kinetics have provided evidence for a "sequential" mechanism.

@article{doi10310910409238809088226,
    author = "Mannervik, Bengt and Danielson, U. Helena and Ketterer, B",
    title = "Glutathione Transferases—Structure and Catalytic Activit",
    year = "1988",
    journal = "Critical Reviews in Biochemistry",
    abstract = {The glutathione transferases are recognized as important catalysts in the biotransformation of xenobiotics, including drugs as well as environmental pollutants. Multiple forms exist, and numerous transferases from mammalian tissues, insects, and plants have been isolated and characterized. Enzymatic properties, reactions with antibodies, and structural characteristics have been used for classification of the glutathione transferases. The cytosolic mammalian enzymes could be grouped into three distinct classes--Alpha, Mu, and Pi; the microsomal glutathione transferase differs greatly from all the cytosolic enzymes. Members of each enzyme class have been identified in human, rat, and mouse tissues. Comparison of known primary structures of representatives of each class suggests a divergent evolution of the enzyme proteins from a common precursor. Products of oxidative metabolism such as organic hydroperoxides, epoxides, quinones, and activated alkenes are possible "natural" substrates for the glutathione transferases. Particularly noteworthy are 4-hydroxyalkenals, which are among the best substrates found. Homologous series of substrates give information about the properties of the corresponding binding site. The catalytic mechanism and the active-site topology have been probed also by use of chiral substrates. Steady-state kinetics have provided evidence for a "sequential" mechanism.},
    url = "https://doi.org/10.3109/10409238809088226",
    doi = "10.3109/10409238809088226",
    openalex = "W1969419384",
    references = "doi10100797894017102682, doi1010160160932778900819, doi101016s0021925819420838, doi101016s0021925820818420, doi101016s0065230x08608489, doi101016s0076687981770460, doi101073pnas82217202, doi101126science6351251, doi105962bhltitle7320, openalexw1589769838"
}

Overlapping genomic clones containing the entire sequence of the human angiotensin I-converting enzyme (ACE) gene were isolated from a lamda phage human DNA library. This gene spans 21 kilobases (kb) and comprises 26 exons, ranging in size from 88 to 481 base pairs. Intron-exon boundaries were sequenced and the relative positions of the exons were mapped. The two different mRNAs transcribed from the ACE gene were assigned to their respective exons. The large endothelial type ACE mRNA (4.3 kb long) is transcribed from exon 1 to exon 26, excluding exon 13. The 3-kb long testicular ACE mRNA is transcribed from exon 13 to exon 26. Exon 13 encodes for the 67 amino acids of the NH2-terminal region of the testicular ACE, whereas downstream exons encode a sequence common to both isozymes. The gene duplication suggested by the internal homology of the endothelial ACE mRNA is now confirmed by the presence of two homologous clusters of eight exons (exons 4-11 and exons 17-24) having similar sizes and codon phases at exon-intron boundaries. The presence of two alternate promoters was investigated by ribonuclease protection assays. The different 5' ends of the two ACE transcripts revealed a promoter for the endothelial ACE mRNA in the 5'-flanking region of the first exon and a promoter for the testicular ACE mRNA situated in intron 12.

@article{doi101016s0021925818986266,
    author = "Hübert, C. and Houot, Anne-Marie and Corvol, Pierre and Soubrier, F",
    title = "Structure of the angiotensin I-converting enzyme gene. Two alternate promoters correspond to evolutionary steps of a duplicated gene",
    year = "1991",
    journal = "Journal of Biological Chemistry",
    abstract = "Overlapping genomic clones containing the entire sequence of the human angiotensin I-converting enzyme (ACE) gene were isolated from a lamda phage human DNA library. This gene spans 21 kilobases (kb) and comprises 26 exons, ranging in size from 88 to 481 base pairs. Intron-exon boundaries were sequenced and the relative positions of the exons were mapped. The two different mRNAs transcribed from the ACE gene were assigned to their respective exons. The large endothelial type ACE mRNA (4.3 kb long) is transcribed from exon 1 to exon 26, excluding exon 13. The 3-kb long testicular ACE mRNA is transcribed from exon 13 to exon 26. Exon 13 encodes for the 67 amino acids of the NH2-terminal region of the testicular ACE, whereas downstream exons encode a sequence common to both isozymes. The gene duplication suggested by the internal homology of the endothelial ACE mRNA is now confirmed by the presence of two homologous clusters of eight exons (exons 4-11 and exons 17-24) having similar sizes and codon phases at exon-intron boundaries. The presence of two alternate promoters was investigated by ribonuclease protection assays. The different 5' ends of the two ACE transcripts revealed a promoter for the endothelial ACE mRNA in the 5'-flanking region of the first exon and a promoter for the testicular ACE mRNA situated in intron 12.",
    url = "https://doi.org/10.1016/s0021-9258(18)98626-6",
    doi = "10.1016/s0021-9258(18)98626-6",
    openalex = "W2148571591",
    references = "doi101002j146020751988tb03124x"
}

Pyridoxal-5'-phosphate-dependent enzymes catalyze manifold reactions in the metabolism of amino acids. A comprehensive comparison of amino acid sequences has shown that most of these enzymes can be assigned to one of three different families of homologous proteins. The sequences of the enzymes of each family were aligned and their homology confirmed by profile analysis. Scrutiny of the reactions catalyzed by the enzymes showed that their affiliation with one of the three structurally defined families correlates in most cases with their regio-specificity. In the largest family, the covalency changes of the substrate occur at the same carbon atom that carries the amino group forming the imine linkage with the coenzyme. This family was thus named alpha family. It comprises glycine hydroxymethyltransferase, glycine C-acetyltransferase, 5-aminolevulinate synthase, 8-amino-7-oxononanoate synthase, all aminotransferases (with the possible exception of subgroup III), a number of other enzymes relatively closely related with the aminotransferases and very likely a certain group of amino acid decarboxylases as well as tryptophanase and tyrosine phenol-lyase which, however, catalyze beta-elimination reactions. The beta family includes L- and D-serine dehydratase, threonine dehydratase, the beta subunit of tryptophan synthase, threonine synthase and cysteine synthase. These enzymes catalyze beta-replacement or beta-elimination reactions. The gamma family incorporates O-succinylhomoserine (thiol-lyase, O-acetylhomoserine (thiol)-lyase, and cystathionine gamma-lyase, which catalyze gamma-replacement or gamma-elimination reactions, as well as cystathionine beta-lyase. The alpha and gamma family might be distantly related with one another, but are clearly not homologous with the beta family. Apparently, the primordial pyridoxal-5'-phosphate-dependent enzymes were regio-specific catalysts, which first specialized for reaction specificity and then for substrate specificity. The following pyridoxal-5'-phosphate-dependent enzymes seem to be unrelated with the alpha, beta or gamma family by the criterion of profile analysis:alanine racemase, selenocysteine synthase, and many amino acid decarboxylases. These enzymes may represent yet other families of B6 enzymes.

@article{doi101111j143210331994tb18577x,
    author = "ALEXANDER, Frederick W. and Sandmeier, Erika and Mehta, Perdeep K. and Christen, Philipp",
    title = "Evolutionary relationships among pyridoxal‐5′‐phosphate‐dependent enzymes",
    year = "1994",
    journal = "European Journal of Biochemistry",
    abstract = "Pyridoxal-5'-phosphate-dependent enzymes catalyze manifold reactions in the metabolism of amino acids. A comprehensive comparison of amino acid sequences has shown that most of these enzymes can be assigned to one of three different families of homologous proteins. The sequences of the enzymes of each family were aligned and their homology confirmed by profile analysis. Scrutiny of the reactions catalyzed by the enzymes showed that their affiliation with one of the three structurally defined families correlates in most cases with their regio-specificity. In the largest family, the covalency changes of the substrate occur at the same carbon atom that carries the amino group forming the imine linkage with the coenzyme. This family was thus named alpha family. It comprises glycine hydroxymethyltransferase, glycine C-acetyltransferase, 5-aminolevulinate synthase, 8-amino-7-oxononanoate synthase, all aminotransferases (with the possible exception of subgroup III), a number of other enzymes relatively closely related with the aminotransferases and very likely a certain group of amino acid decarboxylases as well as tryptophanase and tyrosine phenol-lyase which, however, catalyze beta-elimination reactions. The beta family includes L- and D-serine dehydratase, threonine dehydratase, the beta subunit of tryptophan synthase, threonine synthase and cysteine synthase. These enzymes catalyze beta-replacement or beta-elimination reactions. The gamma family incorporates O-succinylhomoserine (thiol-lyase, O-acetylhomoserine (thiol)-lyase, and cystathionine gamma-lyase, which catalyze gamma-replacement or gamma-elimination reactions, as well as cystathionine beta-lyase. The alpha and gamma family might be distantly related with one another, but are clearly not homologous with the beta family. Apparently, the primordial pyridoxal-5'-phosphate-dependent enzymes were regio-specific catalysts, which first specialized for reaction specificity and then for substrate specificity. The following pyridoxal-5'-phosphate-dependent enzymes seem to be unrelated with the alpha, beta or gamma family by the criterion of profile analysis:alanine racemase, selenocysteine synthase, and many amino acid decarboxylases. These enzymes may represent yet other families of B6 enzymes.",
    url = "https://doi.org/10.1111/j.1432-1033.1994.tb18577.x",
    doi = "10.1111/j.1432-1033.1994.tb18577.x",
    openalex = "W1861199552"
}

@article{doi101021tx960072x,
    author = "Armstrong, Richard N.",
    title = "Structure, Catalytic Mechanism, and Evolution of the Glutathione Transferases",
    year = "1997",
    journal = "Chemical Research in Toxicology",
    url = "https://doi.org/10.1021/tx960072x",
    doi = "10.1021/tx960072x",
    openalex = "W2074461690",
    references = "doi101002med2610030204, doi101016s0021925818667481, doi101016s0021925819502198, doi101042bj0790516, doi101042bj2720281, doi101042bj2820305, doi101107s0021889891004399, doi101111j143210331994tb18666x, doi101146annurevbi58070189003523, doi105860choice352146"
}

@article{doi101016s0959440x98800961,
    author = "Jansonius, Johan N.",
    title = "Structure, evolution and action of vitamin B6-dependent enzymes",
    year = "1998",
    journal = "Current Opinion in Structural Biology",
    url = "https://doi.org/10.1016/s0959-440x(98)80096-1",
    doi = "10.1016/s0959-440x(98)80096-1",
    openalex = "W2013414388",
    references = "doi101002pro5560040705, doi101016016748389500025p, doi1010160307441278900432, doi101016s0021925819779137, doi101021bi9700429, doi101021bi970630m, doi101073pnas554712, doi101111j143210331993tb17953x, doi101111j143210331994tb18577x, doi101111j143210331994tb18816x"
}

The splicing of transfer RNA precursors is similar in Eucarya and Archaea. In both kingdoms an endonuclease recognizes the splice sites and releases the intron, but the mechanism of splice site recognition is different in each kingdom. The crystal structure of the endonuclease from the archaeon Methanococcus jannaschii was determined to a resolution of 2.3 angstroms. The structure indicates that the cleavage reaction is similar to that of ribonuclease A and the arrangement of the active sites is conserved between the archaeal and eucaryal enzymes. These results suggest an evolutionary pathway for splice site recognition.

@article{doi101126science2805361279,
    author = "Li, Hong and Trotta, Christopher R. and Abelson, John",
    title = "Crystal Structure and Evolution of a Transfer RNA Splicing Enzyme",
    year = "1998",
    journal = "Science",
    abstract = "The splicing of transfer RNA precursors is similar in Eucarya and Archaea. In both kingdoms an endonuclease recognizes the splice sites and releases the intron, but the mechanism of splice site recognition is different in each kingdom. The crystal structure of the endonuclease from the archaeon Methanococcus jannaschii was determined to a resolution of 2.3 angstroms. The structure indicates that the cleavage reaction is similar to that of ribonuclease A and the arrangement of the active sites is conserved between the archaeal and eucaryal enzymes. These results suggest an evolutionary pathway for splice site recognition.",
    url = "https://doi.org/10.1126/science.280.5361.279",
    doi = "10.1126/science.280.5361.279",
    openalex = "W2051698639",
    references = "doi101016002228367190324x, doi101016s0092867400802706, doi101038351371a0, doi101038356083a0, doi101093nar24203974, doi101107s0021889888007903, doi101107s0021889892009944, doi101107s0108767390010224, doi101107s0108767391001071, doi101107s0907444994003112"
}

The P450 enzymes (mixed function oxidases, cytochrome P450 monooxygenases), a diverse class of enzymes found in virtually all insect tissues, fulfill many important tasks, from the synthesis and degradation of ecdysteroids and juvenile hormones to the metabolism of foreign chemicals of natural or synthetic origin. This diversity in function is achieved by a diversity in structure, as insect genomes probably carry about 100 P450 genes, sometimes arranged in clusters, and each coding for a different P450 enzyme. Both microsomal and mitochondrial P450s are present in insects and are best studied by heterologous expression of their cDNA and reconstitution of purified enzymes. P450 genes are under complex regulation, with induction playing a central role in the adaptation to plant chemicals and regulatory mutations playing a central role in insecticide resistance. Polymorphisms in induction or constitutive expression allow insects to scan their P450 gene repertoire for the appropriate response to chemical insults, and these evolutionary pressures in turn maintain P450 diversity.

@article{doi101146annurevento441507,
    author = "Feyereisen, René",
    title = "INSECT P450 ENZYMES",
    year = "1999",
    journal = "Annual Review of Entomology",
    abstract = "The P450 enzymes (mixed function oxidases, cytochrome P450 monooxygenases), a diverse class of enzymes found in virtually all insect tissues, fulfill many important tasks, from the synthesis and degradation of ecdysteroids and juvenile hormones to the metabolism of foreign chemicals of natural or synthetic origin. This diversity in function is achieved by a diversity in structure, as insect genomes probably carry about 100 P450 genes, sometimes arranged in clusters, and each coding for a different P450 enzyme. Both microsomal and mitochondrial P450s are present in insects and are best studied by heterologous expression of their cDNA and reconstitution of purified enzymes. P450 genes are under complex regulation, with induction playing a central role in the adaptation to plant chemicals and regulatory mutations playing a central role in insecticide resistance. Polymorphisms in induction or constitutive expression allow insects to scan their P450 gene repertoire for the appropriate response to chemical insults, and these evolutionary pressures in turn maintain P450 diversity.",
    url = "https://doi.org/10.1146/annurev.ento.44.1.507",
    doi = "10.1146/annurev.ento.44.1.507",
    openalex = "W2080895359"
}

The glutathione transferases (GSTs; also known as glutathione S-transferases) are major phase II detoxification enzymes found mainly in the cytosol. In addition to their role in catalysing the conjugation of electrophilic substrates to glutathione (GSH), these enzymes also carry out a range of other functions. They have peroxidase and isomerase activities, they can inhibit the Jun N-terminal kinase (thus protecting cells against H(2)O(2)-induced cell death), and they are able to bind non-catalytically a wide range of endogenous and exogenous ligands. Cytosolic GSTs of mammals have been particularly well characterized, and were originally classified into Alpha, Mu, Pi and Theta classes on the basis of a combination of criteria such as substrate/inhibitor specificity, primary and tertiary structure similarities and immunological identity. Non-mammalian GSTs have been much less well characterized, but have provided a disproportionately large number of three-dimensional structures, thus extending our structure-function knowledge of the superfamily as a whole. Moreover, several novel classes identified in non-mammalian species have been subsequently identified in mammals, sometimes carrying out functions not previously associated with GSTs. These studies have revealed that the GSTs comprise a widespread and highly versatile superfamily which show similarities to non-GST stress-related proteins. Independent classification systems have arisen for groups of organisms such as plants and insects. This review surveys the classification of GSTs in non-mammalian sources, such as bacteria, fungi, plants, insects and helminths, and attempts to relate them to the more mainstream classification system for mammalian enzymes. The implications of this classification with regard to the evolution of GSTs are discussed.

@article{doi101042026460213600001,
    author = "Sheehan, David and MEADE, Gerardene and Foley, Vivienne and DOWD, Catriona A.",
    title = "Structure, function and evolution of glutathione transferases: implications for classification of non-mammalian members of an ancient enzyme superfamily",
    year = "2001",
    journal = "Biochemical Journal",
    abstract = "The glutathione transferases (GSTs; also known as glutathione S-transferases) are major phase II detoxification enzymes found mainly in the cytosol. In addition to their role in catalysing the conjugation of electrophilic substrates to glutathione (GSH), these enzymes also carry out a range of other functions. They have peroxidase and isomerase activities, they can inhibit the Jun N-terminal kinase (thus protecting cells against H(2)O(2)-induced cell death), and they are able to bind non-catalytically a wide range of endogenous and exogenous ligands. Cytosolic GSTs of mammals have been particularly well characterized, and were originally classified into Alpha, Mu, Pi and Theta classes on the basis of a combination of criteria such as substrate/inhibitor specificity, primary and tertiary structure similarities and immunological identity. Non-mammalian GSTs have been much less well characterized, but have provided a disproportionately large number of three-dimensional structures, thus extending our structure-function knowledge of the superfamily as a whole. Moreover, several novel classes identified in non-mammalian species have been subsequently identified in mammals, sometimes carrying out functions not previously associated with GSTs. These studies have revealed that the GSTs comprise a widespread and highly versatile superfamily which show similarities to non-GST stress-related proteins. Independent classification systems have arisen for groups of organisms such as plants and insects. This review surveys the classification of GSTs in non-mammalian sources, such as bacteria, fungi, plants, insects and helminths, and attempts to relate them to the more mainstream classification system for mammalian enzymes. The implications of this classification with regard to the evolution of GSTs are discussed.",
    url = "https://doi.org/10.1042/0264-6021:3600001",
    doi = "10.1042/0264-6021:3600001",
    openalex = "W2097224528",
    references = "doi101021tx960072x, doi10103837918, doi101042bj3000271, doi10108010715769900300851, doi101093emboj1851321, doi101146annurevarplant471127, doi101146annurevbi62070193002125, doi101146annurevento451371, doi10310910409238809088226, doi10310910409239509083491"
}

The glutathione transferases (GSTs; also known as glutathione S-transferases) are major phase II detoxification enzymes found mainly in the cytosol. In addition to their role in catalysing the conjugation of electrophilic substrates to glutathione (GSH), these enzymes also carry out a range of other functions. They have peroxidase and isomerase activities, they can inhibit the Jun N-terminal kinase (thus protecting cells against H2O2-induced cell death), and they are able to bind non-catalytically a wide range of endogenous and exogenous ligands. Cytosolic GSTs of mammals have been particularly well characterized, and were originally classified into Alpha, Mu, Pi and Theta classes on the basis of a combination of criteria such as substrate/inhibitor specificity, primary and tertiary structure similarities and immunological identity. Non-mammalian GSTs have been much less well characterized, but have provided a disproportionately large number of three-dimensional structures, thus extending our structure–function knowledge of the superfamily as a whole. Moreover, several novel classes identified in non-mammalian species have been subsequently identified in mammals, sometimes carrying out functions not previously associated with GSTs. These studies have revealed that the GSTs comprise a widespread and highly versatile superfamily which show similarities to non-GST stress-related proteins. Independent classification systems have arisen for groups of organisms such as plants and insects. This review surveys the classification of GSTs in non-mammalian sources, such as bacteria, fungi, plants, insects and helminths, and attempts to relate them to the more mainstream classification system for mammalian enzymes. The implications of this classification with regard to the evolution of GSTs are discussed.

@article{doi101042bj3600001,
    author = "Sheehan, David and MEADE, Gerardene and Foley, Vivienne and DOWD, Catriona A.",
    title = "Structure, function and evolution of glutathione transferases: implications for classification of non-mammalian members of an ancient enzyme superfamily",
    year = "2001",
    journal = "Biochemical Journal",
    abstract = "The glutathione transferases (GSTs; also known as glutathione S-transferases) are major phase II detoxification enzymes found mainly in the cytosol. In addition to their role in catalysing the conjugation of electrophilic substrates to glutathione (GSH), these enzymes also carry out a range of other functions. They have peroxidase and isomerase activities, they can inhibit the Jun N-terminal kinase (thus protecting cells against H2O2-induced cell death), and they are able to bind non-catalytically a wide range of endogenous and exogenous ligands. Cytosolic GSTs of mammals have been particularly well characterized, and were originally classified into Alpha, Mu, Pi and Theta classes on the basis of a combination of criteria such as substrate/inhibitor specificity, primary and tertiary structure similarities and immunological identity. Non-mammalian GSTs have been much less well characterized, but have provided a disproportionately large number of three-dimensional structures, thus extending our structure–function knowledge of the superfamily as a whole. Moreover, several novel classes identified in non-mammalian species have been subsequently identified in mammals, sometimes carrying out functions not previously associated with GSTs. These studies have revealed that the GSTs comprise a widespread and highly versatile superfamily which show similarities to non-GST stress-related proteins. Independent classification systems have arisen for groups of organisms such as plants and insects. This review surveys the classification of GSTs in non-mammalian sources, such as bacteria, fungi, plants, insects and helminths, and attempts to relate them to the more mainstream classification system for mammalian enzymes. The implications of this classification with regard to the evolution of GSTs are discussed.",
    url = "https://doi.org/10.1042/bj3600001",
    doi = "10.1042/bj3600001",
    openalex = "W4231680606"
}

@article{doi101038nsmb767,
    author = "Harel, Michal and Aharoni, Amir and Gaidukov, Leonid and Brumshtein, Boris and Khersonsky, Olga and Meged, Ran and Dvir, Hay and Ravelli, Raimond B. G. and McCarthy, Andrew A. and Toker, Lilly and Silman, Israel and Sussman, Joel L. and Tawfik, Dan S.",
    title = "Structure and evolution of the serum paraoxonase family of detoxifying and anti-atherosclerotic enzymes",
    year = "2004",
    journal = "Nature Structural \& Molecular Biology",
    url = "https://doi.org/10.1038/nsmb767",
    doi = "10.1038/nsmb767",
    openalex = "W2161414810",
    references = "doi101007s0021000308331, doi1010160014579391809623, doi101016002228367190324x, doi101016s0968000400016261, doi101016s1388198100001530, doi10103828406, doi10103835025203, doi101073pnas942312291, doi101074jbc27563957, doi10116101atv18101617"
}

Pyridoxal phosphate (PLP)-dependent enzymes are unrivaled in the diversity of reactions that they catalyze. New structural data have paved the way for targeted mutagenesis and mechanistic studies and have provided a framework for interpretation of those results. Together, these complementary approaches yield new insight into function, particularly in understanding the origins of substrate and reaction type specificity. The combination of new sequences and structures enables better reconstruction of their evolutionary heritage and illuminates unrecognized similarities within this diverse group of enzymes. The important metabolic roles of many PLP-dependent enzymes drive efforts to design specific inhibitors, which are now guided by the availability of comprehensive structural and functional databases. Better understanding of the function of this important group of enzymes is crucial not only for inhibitor design, but also for the design of improved protein-based catalysts.

@article{doi101146annurevbiochem73011303074021,
    author = "Eliot, Andrew C. and Kirsch, Jack F.",
    title = "Pyridoxal Phosphate Enzymes: Mechanistic, Structural, and Evolutionary Considerations",
    year = "2004",
    journal = "Annual Review of Biochemistry",
    abstract = "Pyridoxal phosphate (PLP)-dependent enzymes are unrivaled in the diversity of reactions that they catalyze. New structural data have paved the way for targeted mutagenesis and mechanistic studies and have provided a framework for interpretation of those results. Together, these complementary approaches yield new insight into function, particularly in understanding the origins of substrate and reaction type specificity. The combination of new sequences and structures enables better reconstruction of their evolutionary heritage and illuminates unrecognized similarities within this diverse group of enzymes. The important metabolic roles of many PLP-dependent enzymes drive efforts to design specific inhibitors, which are now guided by the availability of comprehensive structural and functional databases. Better understanding of the function of this important group of enzymes is crucial not only for inhibitor design, but also for the design of improved protein-based catalysts.",
    url = "https://doi.org/10.1146/annurev.biochem.73.011303.074021",
    doi = "10.1146/annurev.biochem.73.011303.074021",
    openalex = "W2110094991",
    references = "doi101016s0959440x98800961"
}

BACKGROUND: Most studies of molecular evolution are focused on individual genes and proteins. However, understanding the design principles and evolutionary properties of molecular networks requires a system-wide perspective. In the present work we connect molecular evolution on the gene level with system properties of a cellular metabolic network. In contrast to protein interaction networks, where several previous studies investigated the molecular evolution of proteins, metabolic networks have a relatively well-defined global function. The ability to consider fluxes in a metabolic network allows us to relate the functional role of each enzyme in a network to its rate of evolution. RESULTS: Our results, based on the yeast metabolic network, demonstrate that important evolutionary processes, such as the fixation of single nucleotide mutations, gene duplications, and gene deletions, are influenced by the structure and function of the network. Specifically, central and highly connected enzymes evolve more slowly than less connected enzymes. Also, enzymes carrying high metabolic fluxes under natural biological conditions experience higher evolutionary constraints. Genes encoding enzymes with high connectivity and high metabolic flux have higher chances to retain duplicates in evolution. In contrast to protein interaction networks, highly connected enzymes are no more likely to be essential compared to less connected enzymes. CONCLUSION: The presented analysis of evolutionary constraints, gene duplication, and essentiality demonstrates that the structure and function of a metabolic network shapes the evolution of its enzymes. Our results underscore the need for systems-based approaches in studies of molecular evolution.

@article{doi101186gb200675r39,
    author = "Vitkup, Dennis and Kharchenko, Peter V. and Wagner, Andreas",
    title = "Influence of metabolic network structure and function on enzyme evolution",
    year = "2006",
    journal = "Genome biology",
    abstract = "BACKGROUND: Most studies of molecular evolution are focused on individual genes and proteins. However, understanding the design principles and evolutionary properties of molecular networks requires a system-wide perspective. In the present work we connect molecular evolution on the gene level with system properties of a cellular metabolic network. In contrast to protein interaction networks, where several previous studies investigated the molecular evolution of proteins, metabolic networks have a relatively well-defined global function. The ability to consider fluxes in a metabolic network allows us to relate the functional role of each enzyme in a network to its rate of evolution. RESULTS: Our results, based on the yeast metabolic network, demonstrate that important evolutionary processes, such as the fixation of single nucleotide mutations, gene duplications, and gene deletions, are influenced by the structure and function of the network. Specifically, central and highly connected enzymes evolve more slowly than less connected enzymes. Also, enzymes carrying high metabolic fluxes under natural biological conditions experience higher evolutionary constraints. Genes encoding enzymes with high connectivity and high metabolic flux have higher chances to retain duplicates in evolution. In contrast to protein interaction networks, highly connected enzymes are no more likely to be essential compared to less connected enzymes. CONCLUSION: The presented analysis of evolutionary constraints, gene duplication, and essentiality demonstrates that the structure and function of a metabolic network shapes the evolution of its enzymes. Our results underscore the need for systems-based approaches in studies of molecular evolution.",
    url = "https://doi.org/10.1186/gb-2006-7-5-r39",
    doi = "10.1186/gb-2006-7-5-r39",
    openalex = "W2169336096",
    references = "doi1010160022283670900574, doi101016s0092867400816414, doi10103835075138, doi101038nature00935, doi101038nature01644, doi101038nature750, doi101073pnas232349399, doi101093nar25173389, doi101093oxfordjournalsmolbeva026236, doi101093oxfordjournalsmolbeva040153"
}

@article{doi101016jjmb200805038,
    author = "Griffin, Michael D. W. and Dobson, Renwick C. J. and Pearce, F. Grant and Antonio, Laurence and Whitten, Andrew E. and Liew, Chu Kong and Mackay, Joel P. and Trewhella, Jill and Jameson, Geoffrey B. and Perugini, Matthew A. and Gerrard, Juliet A.",
    title = "Evolution of Quaternary Structure in a Homotetrameric Enzyme",
    year = "2008",
    journal = "Journal of Molecular Biology",
    url = "https://doi.org/10.1016/j.jmb.2008.05.038",
    doi = "10.1016/j.jmb.2008.05.038",
    openalex = "W2066327917",
    references = "doi101016c20130041308, doi101016s0006349500767130, doi101038355033a0, doi101038nature02261, doi101107s0021889892001663, doi101107s0021889895007047, doi101107s0108767390010224, doi101107s0907444996012255, doi101126science28654451700, openalexw255996521"
}

Dihydrodipicolinate synthase (DHDPS) catalyzes the first committed step of the lysine biosynthetic pathway. The tetrameric structure of DHDPS is thought to be essential for enzymatic activity, as isolated dimeric mutants of Escherichia coli DHDPS possess less than 2.5% that of the activity of the wild-type tetramer. It has recently been proposed that the dimeric form lacks activity due to increased dynamics. Tetramerization, by buttressing two dimers together, reduces dynamics in the dimeric unit and explains why all active bacterial DHDPS enzymes to date have been shown to be homo-tetrameric. However, in this study we demonstrate for the first time that DHDPS from methicillin-resistant Staphylococcus aureus (MRSA) exists in a monomer-dimer equilibrium in solution. Fluorescence-detected analytical ultracentrifugation was employed to show that the dimerization dissociation constant of MRSA-DHDPS is 33 nm in the absence of substrates and 29 nm in the presence of (S)-aspartate semialdehyde (ASA), but is 20-fold tighter in the presence of the substrate pyruvate (1.6 nm). The MRSA-DHDPS dimer exhibits a ping-pong kinetic mechanism (k(cat)=70+/-2 s(-1), K(m)(Pyruvate)=0.11+/-0.01 mm, and K(m)(ASA)=0.22+/-0.02 mm) and shows ASA substrate inhibition with a K(si)(ASA) of 2.7+/-0.9 mm. We also demonstrate that unlike the E. coli tetramer, the MRSA-DHDPS dimer is insensitive to lysine inhibition. The near atomic resolution (1.45 A) crystal structure confirms the dimeric quaternary structure and reveals that the dimerization interface of the MRSA enzyme is more extensive in buried surface area and noncovalent contacts than the equivalent interface in tetrameric DHDPS enzymes from other bacterial species. These data provide a detailed mechanistic insight into DHDPS catalysis and the evolution of quaternary structure of this important bacterial enzyme.

@article{doi101074jbcm804231200,
    author = "Burgess, Benjamin R. and Dobson, Renwick C. J. and Bailey, Michael F. and Atkinson, Sarah C. and Griffin, Michael D. W. and Jameson, Geoffrey B. and Parker, Michael W. and Gerrard, Juliet A. and Perugini, Matthew A.",
    title = "Structure and Evolution of a Novel Dimeric Enzyme from a Clinically Important Bacterial Pathogen",
    year = "2008",
    journal = "Journal of Biological Chemistry",
    abstract = "Dihydrodipicolinate synthase (DHDPS) catalyzes the first committed step of the lysine biosynthetic pathway. The tetrameric structure of DHDPS is thought to be essential for enzymatic activity, as isolated dimeric mutants of Escherichia coli DHDPS possess less than 2.5\% that of the activity of the wild-type tetramer. It has recently been proposed that the dimeric form lacks activity due to increased dynamics. Tetramerization, by buttressing two dimers together, reduces dynamics in the dimeric unit and explains why all active bacterial DHDPS enzymes to date have been shown to be homo-tetrameric. However, in this study we demonstrate for the first time that DHDPS from methicillin-resistant Staphylococcus aureus (MRSA) exists in a monomer-dimer equilibrium in solution. Fluorescence-detected analytical ultracentrifugation was employed to show that the dimerization dissociation constant of MRSA-DHDPS is 33 nm in the absence of substrates and 29 nm in the presence of (S)-aspartate semialdehyde (ASA), but is 20-fold tighter in the presence of the substrate pyruvate (1.6 nm). The MRSA-DHDPS dimer exhibits a ping-pong kinetic mechanism (k(cat)=70+/-2 s(-1), K(m)(Pyruvate)=0.11+/-0.01 mm, and K(m)(ASA)=0.22+/-0.02 mm) and shows ASA substrate inhibition with a K(si)(ASA) of 2.7+/-0.9 mm. We also demonstrate that unlike the E. coli tetramer, the MRSA-DHDPS dimer is insensitive to lysine inhibition. The near atomic resolution (1.45 A) crystal structure confirms the dimeric quaternary structure and reveals that the dimerization interface of the MRSA enzyme is more extensive in buried surface area and noncovalent contacts than the equivalent interface in tetrameric DHDPS enzymes from other bacterial species. These data provide a detailed mechanistic insight into DHDPS catalysis and the evolution of quaternary structure of this important bacterial enzyme.",
    url = "https://doi.org/10.1074/jbc.m804231200",
    doi = "10.1074/jbc.m804231200",
    openalex = "W2001904989",
    references = "doi101016jjmb200805038"
}

The Carbohydrate-Active Enzyme (CAZy) database is a knowledge-based resource specialized in the enzymes that build and breakdown complex carbohydrates and glycoconjugates. As of September 2008, the database describes the present knowledge on 113 glycoside hydrolase, 91 glycosyltransferase, 19 polysaccharide lyase, 15 carbohydrate esterase and 52 carbohydrate-binding module families. These families are created based on experimentally characterized proteins and are populated by sequences from public databases with significant similarity. Protein biochemical information is continuously curated based on the available literature and structural information. Over 6400 proteins have assigned EC numbers and 700 proteins have a PDB structure. The classification (i) reflects the structural features of these enzymes better than their sole substrate specificity, (ii) helps to reveal the evolutionary relationships between these enzymes and (iii) provides a convenient framework to understand mechanistic properties. This resource has been available for over 10 years to the scientific community, contributing to information dissemination and providing a transversal nomenclature to glycobiologists. More recently, this resource has been used to improve the quality of functional predictions of a number genome projects by providing expert annotation. The CAZy resource resides at URL: http://www.cazy.org/.

@article{doi101093nargkn663,
    author = "Cantarel, Brandi L. and Coutinho, P. M. and Rancurel, Corinne and Bernard, Thomas and Lombard, Vincent and Henrissat, Bernard",
    title = "The Carbohydrate-Active EnZymes database (CAZy): an expert resource for Glycogenomics",
    year = "2008",
    journal = "Nucleic Acids Research",
    abstract = "The Carbohydrate-Active Enzyme (CAZy) database is a knowledge-based resource specialized in the enzymes that build and breakdown complex carbohydrates and glycoconjugates. As of September 2008, the database describes the present knowledge on 113 glycoside hydrolase, 91 glycosyltransferase, 19 polysaccharide lyase, 15 carbohydrate esterase and 52 carbohydrate-binding module families. These families are created based on experimentally characterized proteins and are populated by sequences from public databases with significant similarity. Protein biochemical information is continuously curated based on the available literature and structural information. Over 6400 proteins have assigned EC numbers and 700 proteins have a PDB structure. The classification (i) reflects the structural features of these enzymes better than their sole substrate specificity, (ii) helps to reveal the evolutionary relationships between these enzymes and (iii) provides a convenient framework to understand mechanistic properties. This resource has been available for over 10 years to the scientific community, contributing to information dissemination and providing a transversal nomenclature to glycobiologists. More recently, this resource has been used to improve the quality of functional predictions of a number genome projects by providing expert annotation. The CAZy resource resides at URL: http://www.cazy.org/.",
    url = "https://doi.org/10.1093/nar/gkn663",
    doi = "10.1093/nar/gkn663",
    openalex = "W2108929776",
    references = "doi101126science1128691"
}

BACKGROUND: Glutathione-dependent catalysis is a metabolic adaptation to chemical challenges encountered by all life forms. In the course of evolution, nature optimized numerous mechanisms to use glutathione as the most versatile nucleophile for the conversion of a plethora of sulfur-, oxygen- or carbon-containing electrophilic substances. SCOPE OF REVIEW: This comprehensive review summarizes fundamental principles of glutathione catalysis and compares the structures and mechanisms of glutathione-dependent enzymes, including glutathione reductase, glutaredoxins, glutathione peroxidases, peroxiredoxins, glyoxalases 1 and 2, glutathione transferases and MAPEG. Moreover, open mechanistic questions, evolutionary aspects and the physiological relevance of glutathione catalysis are discussed for each enzyme family. MAJOR CONCLUSIONS: It is surprising how little is known about many glutathione-dependent enzymes, how often reaction geometries and acid-base catalysts are neglected, and how many mechanistic puzzles remain unsolved despite almost a century of research. On the one hand, several enzyme families with non-related protein folds recognize the glutathione moiety of their substrates. On the other hand, the thioredoxin fold is often used for glutathione catalysis. Ancient as well as recent structural changes of this fold did not only significantly alter the reaction mechanism, but also resulted in completely different protein functions. GENERAL SIGNIFICANCE: Glutathione-dependent enzymes are excellent study objects for structure-function relationships and molecular evolution. Notably, in times of systems biology, the outcome of models on glutathione metabolism and redox regulation is more than questionable as long as fundamental enzyme properties are neither studied nor understood. Furthermore, several of the presented mechanisms could have implications for drug development. This article is part of a Special Issue entitled Cellular functions of glutathione.

@article{doi101016jbbagen201209018,
    author = "Deponte, Marcel",
    title = "Glutathione catalysis and the reaction mechanisms of glutathione-dependent enzymes",
    year = "2012",
    journal = "Biochimica et Biophysica Acta (BBA) - General Subjects",
    abstract = "BACKGROUND: Glutathione-dependent catalysis is a metabolic adaptation to chemical challenges encountered by all life forms. In the course of evolution, nature optimized numerous mechanisms to use glutathione as the most versatile nucleophile for the conversion of a plethora of sulfur-, oxygen- or carbon-containing electrophilic substances. SCOPE OF REVIEW: This comprehensive review summarizes fundamental principles of glutathione catalysis and compares the structures and mechanisms of glutathione-dependent enzymes, including glutathione reductase, glutaredoxins, glutathione peroxidases, peroxiredoxins, glyoxalases 1 and 2, glutathione transferases and MAPEG. Moreover, open mechanistic questions, evolutionary aspects and the physiological relevance of glutathione catalysis are discussed for each enzyme family. MAJOR CONCLUSIONS: It is surprising how little is known about many glutathione-dependent enzymes, how often reaction geometries and acid-base catalysts are neglected, and how many mechanistic puzzles remain unsolved despite almost a century of research. On the one hand, several enzyme families with non-related protein folds recognize the glutathione moiety of their substrates. On the other hand, the thioredoxin fold is often used for glutathione catalysis. Ancient as well as recent structural changes of this fold did not only significantly alter the reaction mechanism, but also resulted in completely different protein functions. GENERAL SIGNIFICANCE: Glutathione-dependent enzymes are excellent study objects for structure-function relationships and molecular evolution. Notably, in times of systems biology, the outcome of models on glutathione metabolism and redox regulation is more than questionable as long as fundamental enzyme properties are neither studied nor understood. Furthermore, several of the presented mechanisms could have implications for drug development. This article is part of a Special Issue entitled Cellular functions of glutathione.",
    url = "https://doi.org/10.1016/j.bbagen.2012.09.018",
    doi = "10.1016/j.bbagen.2012.09.018",
    openalex = "W1994025158",
    references = "doi1010160378111988900054, doi101016s0021925819420838, doi101016s0021925819778156, doi101016s0891584901004804, doi101038nature02026, doi101038nature02046, doi101042026460213600001, doi101126science1523409, doi101146annurevmicro57030502090938, doi101146annurevpharmtox45120403095857, doi101152physrev000442005, doi10310910409238809088226"
}

UNLABELLED: Drying is a critical post-harvest step in the processing of Chinese medicinal materials; however, the mechanistic links between key processing parameters and final product quality remain incompletely understood. To address this, we conducted a multidimensional investigation into the mechanisms of quality deterioration and metabolic regulation in Rheum palmatum L. during hot-air drying at 45 °C, with a particular focus on the role of slice thickness (2-8 mm). We systematically examined the synergistic effects of thickness and drying time on color evolution, key enzyme activities, and phytochemical composition. The results indicate that color deterioration occurs in two consecutive stages: an initial phase dominated by polyphenol oxidase (PPO)-mediated enzymatic browning, followed by a later stage of non-enzymatic browning. Slice thickness strongly regulated moisture migration, which in turn governed the dynamic retention of bioactive compounds, with 4 mm slices exhibiting optimal preservation of total anthraquinones. The drying kinetics of these optimal slices were most accurately described by the Wang and Singh model (R2 > 0.999). Non-targeted metabolomics further revealed extensive metabolic reprogramming, identifying 652 differentially accumulated metabolites. Pathway enrichment analysis highlighted flavonoid and tyrosine biosynthesis as the most significantly altered pathways. From these data, we delineated a regulatory network involving 7 key metabolites and 10 associated enzymes, providing a mechanistic scaffold for quality formation. This study proposes an optimized drying strategy (4 mm slice thickness with endpoint moisture control) and establishes an integrated "processing-structure-metabolism" framework that links physical drying conditions to biochemical responses. These findings offer a theoretical basis for the precision drying of rhubarb and provide a methodological reference for the processing of other medicinal plants. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-026-01725-3.

@article{doi101007s12298026017253,
    author = "Luo, Wen and Chen, Yingying and Zhou, Jia and Yang, Mingjun and Wang, Yonggang",
    title = "Quality deterioration and metabolic regulation during hot-air drying of Rheum palmatum L.: an integrated analysis of physiology, drying kinetics, non-targeted metabolomics, and enzyme activity dynamics.",
    year = "2026",
    journal = "Physiology and molecular biology of plants: an international journal of functional plant biology",
    abstract = {UNLABELLED: Drying is a critical post-harvest step in the processing of Chinese medicinal materials; however, the mechanistic links between key processing parameters and final product quality remain incompletely understood. To address this, we conducted a multidimensional investigation into the mechanisms of quality deterioration and metabolic regulation in Rheum palmatum L. during hot-air drying at 45 °C, with a particular focus on the role of slice thickness (2-8 mm). We systematically examined the synergistic effects of thickness and drying time on color evolution, key enzyme activities, and phytochemical composition. The results indicate that color deterioration occurs in two consecutive stages: an initial phase dominated by polyphenol oxidase (PPO)-mediated enzymatic browning, followed by a later stage of non-enzymatic browning. Slice thickness strongly regulated moisture migration, which in turn governed the dynamic retention of bioactive compounds, with 4 mm slices exhibiting optimal preservation of total anthraquinones. The drying kinetics of these optimal slices were most accurately described by the Wang and Singh model (R2 > 0.999). Non-targeted metabolomics further revealed extensive metabolic reprogramming, identifying 652 differentially accumulated metabolites. Pathway enrichment analysis highlighted flavonoid and tyrosine biosynthesis as the most significantly altered pathways. From these data, we delineated a regulatory network involving 7 key metabolites and 10 associated enzymes, providing a mechanistic scaffold for quality formation. This study proposes an optimized drying strategy (4 mm slice thickness with endpoint moisture control) and establishes an integrated "processing-structure-metabolism" framework that links physical drying conditions to biochemical responses. These findings offer a theoretical basis for the precision drying of rhubarb and provide a methodological reference for the processing of other medicinal plants. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-026-01725-3.},
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC13125592/",
    doi = "10.1007/s12298-026-01725-3",
    openalex = "W7133218743",
    pmcid = "PMC13125592",
    pmid = "42064629",
    references = "doi101016jcopbio2023102921, doi101016jindcrop2020112985, doi101016jphytochem201802003, doi1010801040839820201765309, doi101111pbi13586, doi101186s1302001701585, doi103389fbioe2020589069, doi103390foods9010101, doi103390ijms222312824, doi103390molecules25173809"
}

Epidermal growth factor (EGF) domain-specific O-linked N-acetylglucosamine transferase (EOGT), a glycosyltransferase (GT) 61 family member, catalyzes O-N-acetylglucosamine (O-GlcNAc) transfer from uridine diphosphate (UDP)-GlcNAc to serine or threonine residues within EGF domains in the endoplasmic reticulum. In this study, we determined the crystal structure of the EOGT-UDP complex and identified the critical residues mediating their interactions, which were validated via site-directed mutagenesis and enzyme activity assays. These residues were conserved in EOGT orthologs across metazoans, and UDP binding occurred independently of divalent metal ions and the canonical Asp-X-Asp motif. Although EOGT catalyzes O-GlcNAcylation, similar to O-GlcNAc transferase (OGT), it shares little sequence similarity with OGT and belongs to a distinct GT family. Instead, EOGT is more closely related to protein O-linked-mannose β1,4-N-acetylglucosaminyltransferase 2 (POMGNT2). Structural comparison with POMGNT2 revealed a conserved triad of one asparagine and two arginine residues, the N-R-R constellation. These elements were conserved across metazoans and green plants (Viridiplantae), suggesting a unifying mechanism of UDP recognition and providing a framework to interpret disease-associated EOGT mutations and assess the evolution of catalytically active GT61 family enzymes.

@article{doi101093pnasnexuspgag115,
    author = "Tashima, Yuko and Nagae, Masamichi and Jiang, Jiaoyang and Okajima, Tetsuya",
    title = "Crystal structure of epidermal growth factor domain-specific O-linked N-acetylglucosamine transferase reveals a conserved N-R-R constellation for uridine diphosphate recognition in the GT61 family.",
    year = "2026",
    journal = "PNAS nexus",
    abstract = "Epidermal growth factor (EGF) domain-specific O-linked N-acetylglucosamine transferase (EOGT), a glycosyltransferase (GT) 61 family member, catalyzes O-N-acetylglucosamine (O-GlcNAc) transfer from uridine diphosphate (UDP)-GlcNAc to serine or threonine residues within EGF domains in the endoplasmic reticulum. In this study, we determined the crystal structure of the EOGT-UDP complex and identified the critical residues mediating their interactions, which were validated via site-directed mutagenesis and enzyme activity assays. These residues were conserved in EOGT orthologs across metazoans, and UDP binding occurred independently of divalent metal ions and the canonical Asp-X-Asp motif. Although EOGT catalyzes O-GlcNAcylation, similar to O-GlcNAc transferase (OGT), it shares little sequence similarity with OGT and belongs to a distinct GT family. Instead, EOGT is more closely related to protein O-linked-mannose β1,4-N-acetylglucosaminyltransferase 2 (POMGNT2). Structural comparison with POMGNT2 revealed a conserved triad of one asparagine and two arginine residues, the N-R-R constellation. These elements were conserved across metazoans and green plants (Viridiplantae), suggesting a unifying mechanism of UDP recognition and providing a framework to interpret disease-associated EOGT mutations and assess the evolution of catalytically active GT61 family enzymes.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC13123520/",
    doi = "10.1093/pnasnexus/pgag115",
    openalex = "W7154503733",
    pmcid = "PMC13123520",
    pmid = "42058885",
    references = "doi101038nature08747, doi101038s41586021038192, doi101093nargkn663, doi101107s0907444904023510, doi101107s0907444904026460, doi101107s0907444909042073, doi101107s0907444909047337, doi101107s0907444910007493, doi101107s0907444913000061, doi101107s2059798319011471"
}