Inhibitory mechanism of tyrosinase inhibitory peptides identified from the mantle of Pinctada martensii

Mantle tissue of pearl oyster is an underappreciated protein resource for functional peptides preparation. This study aimed to identify novel tyrosinase inhibitory peptides from collagen of Pinctada martensii mantle and to elucidate inhibition mechanism against tyrosinase. Collagen peptides of mantle were prepared by enzyme hydrolysis with animal protease. Two novel tyrosinase inhibitory peptides, Val-Leu-Ser-Val-Tyr (VLSLY) and Ile-Val-His-Arg-Lys-Cys-Phe (IVHRKCF), with IC50 values of 0.80 ± 0.03 mM and 1.51 ± 0.10 mM, respectively, were identified using LC-MS/MS methods combined with molecular docking. Moreover, the peptide IVHRKCF showed superior free radical scavenging ability. Hydrogen bonding and hydrophobic interactions were the main drivers of the interaction of peptides with tyrosinase, and IVHRKCF exhibited a more stable affinity. Lineweaver-Burk analysis results indicated that both peptides exhibited a mixed inhibition mechanism. This study provides new insights into the potential use of tyrosinase inhibitors in whitening foods and pharmaceuticals. • Efficient tyrosinase inhibitory peptides screened via specific binding & LC-MS/MS. • Two anti-tyrosinase peptides identified via molecular docking (IC 50 : 0.80±0.03 & 1.51±0.10 mM). • VLSLY/IVHRKCF bind tyrosinase via hydrogen bonds & hydrophobic interactions (mixed inhibition). • Demonstrates tyrosinase inhibitors' potential in whitening foods & pharmaceuticals.