Physico-chemical characteristics, antioxidant activity and efficiency of a peptide isolated from cow colostrum on an experimental model of type 2 diabetes mellitus

The aim of the research is to characterize and study the effect of the peptide with the amino acid sequence ILGKLLSTAAGLLSNL isolated from trypsin hydrolysate of cow colostrum on the indicators of antioxidant protection of laboratory animals against the background of a type 2 diabetes mellitus model. Mass Spectra Analysis was performed by Mascot program using Protein NCBI database. Microsequencing was performed using the BISEQ sequencer and the PGM Ion Torrent high-performance sequencing system. The spatial structure of the isolated peptides was modeled using the Schrodinge rMaestro molecular modeling program. The antioxidant activity of the peptides was determined by the following methods: DPPH, ABTS and FRAP. A polypeptide consisting of 16 amino acids with the following sequence: ILGKLLSTAAGLLSNL and a molecular weight of 1583.05 Da was isolated from trypsin hydrolysate of cow milk. The analysis of the simulated spatial structures of the peptide allowed us to establish that it forms only an alpha structure and belongs to the amphiphilic, total charge of the peptide is +1, the isoelectric point is at level of 10.15. Physicochemical characteristics of the peptide obtained by us suggest that isolated peptide belongs to antioxidant. The experiment established that peptide has antioxidant activity (3.21 mmol eq. Trolox/l). It proved that intragastric administration of peptide daily for 30 days at a dose of 0.9 mg / kg to diabetic rats reduces the level of hyperglycemia and indicators of oxidative stress.