Human colostrum is recognized as a source of bioactive compounds that impact neonatal development, such as antimicrobial peptides. Antimicrobial peptides (AMPs) present some common characteristics, as they are relatively small (<10 kDa), most of them are positively charged and possess α-helical regions. These molecules can protect the newborn against infectious agents such as bacteria, fungi, and viruses. Using an MS-based non-targeted proteomic approach combined with the application of bioinformatic tools, 29 endogenous peptide sequences were annotated (level 2) in human colostrum. These peptides are potentially antifungal and were enriched in glutamic acid (E), phenylalanine (F), lysine (K) and tryptophan (W) residues. Among the precursor proteins, two have a known 3D structure and their fragments are located in the protein core. In addition, in silico analyses revealed that AMPs containing regions of α-helix and random structures, and high aliphatic index (mean of 85.29) tended to be thermostable. In this exploratory work with human colostrum, previously unreported peptides with potential antimicrobial activity were annotated and structurally characterized via bioinformatic tools. Future studies are necessary to confirm peptides’ identification and to determine their concentrations in human colostrum. • 29 endogenous peptide sequences were annotated in human colostrum. • In silico analyses disclosed that potential AMPs have α-helix and random structures. • All the AMPs in human colostrum were enriched in Glu, Phe, Lys, and Trp residues. • Most antimicrobial peptides (AMPs) in human colostrum were potentially antifungal.
Campanhon et al. (Fri,) studied this question.