Unveiling the patterns and mechanisms of time-specific release of multifunctional peptides from cricket protein

Alcalase time-specifically dictated hydrolysis property, peptide profiles and multifunction. • Antioxidant and ACE inhibition positively correlated with structural unfolding related hydrolysis efficacy promotion. • DPP-IV inhibition relied more on characteristics of specific peptide motifs. • Activity-guided multivariate and differential peptide profile analysis revealed candidate peptides. Endpoint-based studies failed to clarify time-resolved hydrolysis properties, bioactivities, peptide profiles, and structural characteristics. Current study aimed to explore the correlations of these characteristics during Alcalase hydrolysis of cricket protein (CP) for 30–300 min. Prolonged hydrolysis increased degree of hydrolysis (DH) to 20.3%, with low-molecular-weight peptides (< 2 kDa) accounting for 88.0%–94.0%. Cricket protein hydrolysates (CPHs) showed strongest antioxidant and angiotensin I-converting enzyme (ACE) inhibitory activities at 30 and 300 min, respectively, whereas dipeptidyl peptidase-IV (DPP-IV) inhibition exhibited a bimodal pattern. Structural analyses demonstrated hydrolysis disrupted ordered CP structure, with α -helix+ β -sheet decreasing by 17.4%–26.5%, alongside lowered surface hydrophobicity and increased sulfhydryl exposure. Antioxidant and ACE inhibition were positively associated with structural unfolding and hydrolysis property promotion, whereas DPP-IV inhibition appeared to relate more to peptide-release characteristics. Activity-guided peptidomics and multivariate analyses prioritized LYPL/VYGPL, SGLFDK/PAALGL, and SGPRLH/FAGPS as candidate peptides potentially associated with antioxidant, ACE inhibitory, and DPP-IV inhibitory activities, respectively. Download: Download high-res image (177KB) Download: Download full-size image