Theoretical rationale and experimental study confirmation of antibacterial and antifungal properties of natural peptide

This article focuses on theoretical explanation of the antibacterial and antifungal activity of the natural peptide mpR2 isolated from pepsin hydrolysate of cow colostrum, and experimental confirmation of its effects in vitro. The isolated polypeptide consisted of 60 amino acid residues and had a molecular weight of 23 kDa. Modeling showed that the spatial structure of mpR2 is represented by an α-helix. The peptide has a hydrophobic domain, its total charge is +2, and the isoelectric point is at the level of 8.9. The obtained biophysical characteristics suggested that the isolated peptide has antibacterial and antifungal activity, which was confirmed by the disco-diffusion method. It was found that the identified peptide mpR2 has antibacterial activity against test strains of bacteria of gram-negative bacterium E.coli ATCC 25922 and gram-positive bacterium B. Subtilis, as well as antifungal activity against yeast diploid fungus C. Albicans, but lower in comparison with the activity of synthetic antibiotics and antifungal drugs.