In Silico Evaluation of Human α-S1-Casein, β-Casein, and κ-Casein as a Source of Bioactive Peptides

Abstract

Human caseins (α-S1, β, and κ-casein) represent a potential source of bioactive peptides with possible therapeutic applications, particularly for neonates. Due to the relevance of obtaining bioactive peptides, an in silico simulation of enzymatic hydrolysis with pepsin (pH > 2) was performed on these proteins using the PeptideCutter tool from Expasy. The resulting fragments were evaluated in silico using various bioinformatics platforms to predict biological activities such as toxicity (ToxinPred 3.0), antimicrobial (CAMPR4), anticancer (AntiCP 2.0), anti-inflammatory (PreAIP), and antioxidant (AnOxPePred 1.0) properties, as well as their overall bioactivity probability (PeptideRanker) and comparison against the BIOPEP-UWM database. A total of 117 peptide fragments were generated: 40 from α-S1-casein, 48 from β-casein, and 29 from κ-casein. Of these, 26 peptides showed scores above 0.5 in PeptideRanker, suggesting potential bioactivity, and 17 were predicted to possess antimicrobial properties, primarily derived from α-S1-casein. Twelve peptides were identified as potentially toxic, with none originating from κ-casein. Additionally, 18 peptides (16 dipeptides and 2 tripeptides) exhibited exact sequence matches with experimentally reported peptides in the BIOPEP-UWM database. The results obtained in this study were compared with previous research, highlighting both similarities and differences in the generated sequences depending on the hydrolysis tool used. Although the results obtained through in silico analysis are encouraging, we emphasize the importance of experimentally confirming the bioactivity of these peptides. This study contributes to the understanding of the bioactive potential of peptides derived from human caseins and underscores their possible role in supporting neonatal health.