Peptides

@article{harada1958the,
    author = "Harada, Kaoru and Fox, Sidney W.",
    title = "The Thermal Condensation of Glutamic Acid and Glycine to Linear Peptides 1",
    year = "1958",
    journal = "Journal of the American Chemical Society",
    url = "https://doi.org/10.1021/ja01544a027",
    doi = "10.1021/ja01544a027",
    number = "11",
    pages = "2694-2697",
    volume = "80"
}

@misc{fox1974from1,
    author = "Fox, S. W. and Jungck, J. R. and Nakashima, T",
    title = "From proteinoid microsphere to comtemporary cell",
    year = "1974",
    howpublished = "formation of internucleotide and peptide bonds by proteinoid particles: Origins Life, v. 5, p. 227-237",
    note = "talkorigins\_source = {true}; raw\_reference = {Fox, S. W., Jungck, J. R., and Nakashima, T., 1974, From proteinoid microsphere to comtemporary cell: formation of internucleotide and peptide bonds by proteinoid particles: Origins Life, v. 5, p. 227-237.}"
}

@article{temussi1976structural5,
    author = "Temussi, P. A. and Paolillo, L. and Ferrara, L. and Benedetti, E. and Andini, S",
    title = "Structural characterization of thermal prebiotic polypeptides",
    year = "1976",
    journal = "Journal of Molecular Evolution, v. 7, p. 105-110",
    note = "talkorigins\_source = {true}; raw\_reference = {Temussi, P. A., Paolillo, L., Ferrara, L., Benedetti, E., and Andini, S., 1976, Structural characterization of thermal prebiotic polypeptides: Journal of Molecular Evolution, v. 7, p. 105-110.}"
}

@article{nakashima1977a3,
    author = "Nakashima, T. and Jungck, J. R. and Fox, S. W. and Lederer, E. and Das, B. C",
    title = "A test for randomness in peptides isolated from a thermal polyamino acid",
    year = "1977",
    journal = "International Journal of Quantum Chemistry, v. QBS4, p. 65-72",
    note = "talkorigins\_source = {true}; raw\_reference = {Nakashima, T., Jungck, J. R., Fox, S. W., Lederer, E., and Das, B. C., 1977, A test for randomness in peptides isolated from a thermal polyamino acid: International Journal of Quantum Chemistry, v. QBS4, p. 65-72.}"
}

@misc{nakashima1981formulation2,
    author = "Nakashima, T. and Fox, S. W",
    title = "Formulation of peptides by single or multiple additions of ATP to suspensions of nucleoproteinoid microparticles",
    year = "1981",
    howpublished = "BioSystems, v. 14, p. 151-161",
    note = "talkorigins\_source = {true}; raw\_reference = {Nakashima, T., and Fox, S. W., 1981, Formulation of peptides by single or multiple additions of ATP to suspensions of nucleoproteinoid microparticles: BioSystems, v. 14, p. 151-161.}"
}

@misc{pivcova1981nmr4,
    author = "Pivcova, H. and Saudek, V. and Drobnik, J. and Vlasak, J",
    title = "NMR study of poly (aspartic acid) I. - and -peptide bonds in poly (aspartic acid) prepared by thermal polycondensation",
    year = "1981",
    howpublished = "Biopolymers, v. 20, p. 1605-1614",
    note = "talkorigins\_source = {true}; raw\_reference = {Pivcova, H., Saudek, V., Drobnik, J., and Vlasak, J., 1981, NMR study of poly (aspartic acid) I. - and -peptide bonds in poly (aspartic acid) prepared by thermal polycondensation: Biopolymers, v. 20, p. 1605-1614.}"
}

@article{nakashima2009a,
    author = "Nakashima, Tadayoshi and Jungck, John R. and Fox, Sidney W. and Lederer, E. and Das, B. C.",
    title = "A test for randomness in peptides isolated from a thermal polyamino acid",
    year = "2009",
    journal = "International Journal of Quantum Chemistry",
    url = "https://doi.org/10.1002/qua.560120708",
    doi = "10.1002/qua.560120708",
    number = "S4",
    pages = "65-72",
    volume = "12"
}

@article{punitha2012structural,
    author = "Punitha, Velmurugan and Jonnalagadda, Raghava Rao and Nair, Balachandran Unni",
    title = "Structural, thermal and enzymatic analysis of naturally occurring and D-amino acid substituted peptides",
    year = "2012",
    journal = "Advances in Bioscience and Biotechnology",
    url = "https://doi.org/10.4236/abb.2012.37111",
    doi = "10.4236/abb.2012.37111",
    number = "07",
    pages = "900-908",
    volume = "03"
}

Proteins on interaction with surfactants are known to undergo structural and functional alterations. These protein-surfactant interactions are crucial for their applications in the cosmetic and pharmaceutical industries. Despite having various studies involving the interactions of albumins with surfactants, most of them are done at a standard pH (pH 7) and temperature (298 K). Peptide-based surfactants can be designed to have multiple amino and carboxylic acid groups, which would allow them to exist as different ionic species at different pH. This paper provides insights in to the interactions between the protein and different ionic forms of the surfactants which exist at different environmental conditions. Three different surfactants, S1, S2, and S3, are designed with one, two, or four pairs of amino and carboxylic acid functions in the headgroup and a fixed 12-carbon aliphatic tail group. The interactions between these multifunctional surfactants and bovine serum albumin (BSA) at different pH and at different temperatures are studied using fluorescence, UV-visible, and CD spectroscopy. All three surfactants resulted in quenching of the fluorescence of BSA. The strength of the BSA-surfactant complexes along with the binding parameters were calculated, and the mechanism of quenching was investigated. The nature of interactions between the surfactants and BSA could be elucidated by calculating the thermodynamic parameters. The results obtained from CD and UV-visible studies also support the conclusions drawn from fluorescence spectroscopy.

@article{doi101021acslangmuir6c00589,
    author = "Gupta, Sumedha and Neelakshi and Jain, Nikita and Ramapanicker, Ramesh",
    title = "Multifunctional Amphicharged Surfactants: Unraveling pH and Thermal Modulation of Their Interactions with Bovine Serum Albumin.",
    year = "2026",
    journal = "Langmuir: the ACS journal of surfaces and colloids",
    abstract = "Proteins on interaction with surfactants are known to undergo structural and functional alterations. These protein-surfactant interactions are crucial for their applications in the cosmetic and pharmaceutical industries. Despite having various studies involving the interactions of albumins with surfactants, most of them are done at a standard pH (pH 7) and temperature (298 K). Peptide-based surfactants can be designed to have multiple amino and carboxylic acid groups, which would allow them to exist as different ionic species at different pH. This paper provides insights in to the interactions between the protein and different ionic forms of the surfactants which exist at different environmental conditions. Three different surfactants, S1, S2, and S3, are designed with one, two, or four pairs of amino and carboxylic acid functions in the headgroup and a fixed 12-carbon aliphatic tail group. The interactions between these multifunctional surfactants and bovine serum albumin (BSA) at different pH and at different temperatures are studied using fluorescence, UV-visible, and CD spectroscopy. All three surfactants resulted in quenching of the fluorescence of BSA. The strength of the BSA-surfactant complexes along with the binding parameters were calculated, and the mechanism of quenching was investigated. The nature of interactions between the surfactants and BSA could be elucidated by calculating the thermodynamic parameters. The results obtained from CD and UV-visible studies also support the conclusions drawn from fluorescence spectroscopy.",
    url = "https://pubmed.ncbi.nlm.nih.gov/42026894/",
    doi = "10.1021/acs.langmuir.6c00589",
    pmid = "42026894"
}

Marine-derived bioactive peptides have attracted increasing attention as value-added functional ingredients. In this study, peptides (<3 kDa) were prepared from yellowfin tuna processing by-products and further fractionated by Sephadex G-25 gel filtration. The major fraction (TBP-MF) exhibited markedly improved compositional homogeneity compared with the unfractionated hydrolysate (TBP), providing a well-defined peptide system for subsequent characterization and biological evaluation. Physicochemical analyses demonstrated that TBP-MF possessed enhanced thermal stability and a more ordered secondary structure, characterized by pronounced β-sheet enrichment, as revealed by TGA/DSC, FTIR, and circular dichroism analyses. Morphological and colloidal characterization further showed that TBP-MF formed relatively uniform lamellar and fibrous assemblies with a narrower particle size distribution and reduced electrostatic stabilization, indicating a higher tendency toward ordered self-association. Peptidomic profiling combined with in silico analysis revealed that TBP-MF was enriched in short peptides with relatively higher PeptideRanker scores and a functional motif distribution containing relatively more neuro-related annotations, although angiotensin-converting enzyme (ACE)- and dipeptidyl peptidase IV (DPP-IV)-related motifs remained predominant in both groups. In differentiated PC12 cells, TBP-MF exhibited excellent cytocompatibility and induced a stable, concentration-dependent increase in the Cell Counting Kit-8 (CCK-8) readout (OD450), indicating enhanced cellular metabolic activity and/or increased cell number. In addition, TBP-MF significantly increased intracellular levels of key neurochemical factors associated with sleep-related regulation, including tetrahydrobiopterin (BH4), serotonin (5-HT), and γ-aminobutyric acid (GABA). Overall, this study highlights yellowfin tuna by-products as a promising marine resource for bioactive peptides and suggests that fractionation-driven structural refinement is associated with neuro-related biological activity in differentiated PC12 cells. These findings support the potential application of marine by-product-derived peptides as functional ingredients in health-related fields.

@article{doi103390cimb48040374,
    author = "Kong, Yaqi and Liu, Yifan and Yang, Haoze and Liang, Xianzhe and Zhao, Min and Javed, Ahsan and Diao, Xiaozhen and Wu, Wenhui",
    title = "Bioactive Peptides from Yellowfin Tuna By-Products: Structural Characterization and Neuro-Related Activities in PC12 Cells.",
    year = "2026",
    journal = "Current issues in molecular biology",
    abstract = "Marine-derived bioactive peptides have attracted increasing attention as value-added functional ingredients. In this study, peptides (<3 kDa) were prepared from yellowfin tuna processing by-products and further fractionated by Sephadex G-25 gel filtration. The major fraction (TBP-MF) exhibited markedly improved compositional homogeneity compared with the unfractionated hydrolysate (TBP), providing a well-defined peptide system for subsequent characterization and biological evaluation. Physicochemical analyses demonstrated that TBP-MF possessed enhanced thermal stability and a more ordered secondary structure, characterized by pronounced β-sheet enrichment, as revealed by TGA/DSC, FTIR, and circular dichroism analyses. Morphological and colloidal characterization further showed that TBP-MF formed relatively uniform lamellar and fibrous assemblies with a narrower particle size distribution and reduced electrostatic stabilization, indicating a higher tendency toward ordered self-association. Peptidomic profiling combined with in silico analysis revealed that TBP-MF was enriched in short peptides with relatively higher PeptideRanker scores and a functional motif distribution containing relatively more neuro-related annotations, although angiotensin-converting enzyme (ACE)- and dipeptidyl peptidase IV (DPP-IV)-related motifs remained predominant in both groups. In differentiated PC12 cells, TBP-MF exhibited excellent cytocompatibility and induced a stable, concentration-dependent increase in the Cell Counting Kit-8 (CCK-8) readout (OD450), indicating enhanced cellular metabolic activity and/or increased cell number. In addition, TBP-MF significantly increased intracellular levels of key neurochemical factors associated with sleep-related regulation, including tetrahydrobiopterin (BH4), serotonin (5-HT), and γ-aminobutyric acid (GABA). Overall, this study highlights yellowfin tuna by-products as a promising marine resource for bioactive peptides and suggests that fractionation-driven structural refinement is associated with neuro-related biological activity in differentiated PC12 cells. These findings support the potential application of marine by-product-derived peptides as functional ingredients in health-related fields.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC13114659/",
    doi = "10.3390/cimb48040374",
    pmcid = "PMC13114659",
    pmid = "42042034"
}