Molecular Interactions of Bioactive Peptides with Proteins and DNA

Background: This study investigates the molecular recognition of two biologically active peptides (P1 and P2) by key biomacromolecular targets. The studied peptides were previously identified in Babylon snail hydrolysates and have been shown to exhibit antioxidant and cytotoxic activities against Caco-2 colorectal cancer cells. Given their reported biological potential, we decided to investigate both compounds from a different perspective. Their interactions with human serum albumin (HSA), alpha-1-acid glycoprotein (AAG), lysozyme (LYS), immunoglobulin G (IgG), and DNA were evaluated. Methods, Results and Conclusions: Spectroscopic analyses revealed concentration-dependent binding of the studied peptides to plasma proteins under investigations. Notably, peptide binding did not substantially alter the secondary structure of the target proteins, indicating that complex formation occurs without significant structural perturbation. Molecular docking further supported the formation of peptide–protein complexes, highlighting the contribution of hydrogen bonding and hydrophobic contacts to molecular recognition. The combined spectroscopic and docking results were consistent with a predominantly non-intercalative, possibly minor-groove-associated interaction with ctDNA. Taken together, these findings provide a comparative physicochemical characterization of the interactions of P1 and P2 with selected proteins and ctDNA. These findings provide insight into the molecular recognition properties of P1 and P2 and support further investigation of their biological relevance.