. In this work, the isolation and analysis of the peptide fraction of the secretory fluid of Clarias gariepinus was carried out. Isolation was carried out by reprecipitation methods and was accompanied by intermediate purifications on sorbents. The peptide nature of the isolated fraction was confirmed by IR spectroscopy. Mass spectrometric analysis of the peptide fraction of the secretory fluid extract showed that well-retained peptides with a molecular weight of 2000-3000 Da, as well as shorter hydrophilic peptides predominate in the composition. Peptide sequences were determined using Proteome Discoverer 1.4 software (Thermo Scientific) using the UniProt amino acid sequence database (uniprot-catfish + AND + organism__Clarias + gariepinus + [13013]). 14547 peptide sequences belonging to 131 protein groups were found programmatically. It was shown that secretory fluid extract contains a large number of peptides belonging to various classes of Clarias gariepinus proteome proteins (beta-actins, cytochrome family, heat shock proteins, myostatin, NADH-dehydrogenase complex, etc.), which determine a wide range of biological properties characteristic for skin secretion of fish. Further study of the skin secretion of clarius seems promising in terms of fractionation of the peptide pool and determination of the pharmacological activity of a narrower fraction.
Clarias gariepinus, skin secretion, peptide fractions, mass spectrometry, sequencing
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