Skin-care functions of peptides prepared from Chinese quince seed protein: Sequences analysis, tyrosinase inhibition and molecular docking study

Abstract

The hydrolysis of proteins could produce more bioactive moieties. To obtain more bioactivities, Chinese quince seed protein was hydrolyzed by papain to produce biological peptides. After ultrafiltration, gel filtration chromatography, and reversed phase high performance liquid chromatography purifications, two novel peptides were successfully prepared. Matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF-TOF) tandem mass spectrometer was applied to identified the amino acid sequences of these two purified peptides, and they were Asparagine-Tyrosine-Arginine-Arginine-Glutamic acid (NYRRE, 737.059 Da) and Arginine-Histidine-Alanine-Lysine-Phenylalanine (RHAKF, 658.010 Da), respectively. In the antioxidant assays, RHAKF showed stronger DPPH, superoxide anion radicals scavenging activity and lipid peroxidation inhibition than NYRRE. Moreover, RHAKF exhibited better copper chelating activity than NYRRE, as its IC50 value was 0.93 mg/mL and it was lower than that of NYRRE (2.11 mg/mL). The tyrosinase inhibition evaluation demonstrated that RHAKF exhibited much better inhibitory activity than NYRRE. To explain this phenomenon, molecular docking simulation was used to reveal the interactions between tyrosinase and peptides. More docking sites were observed between RHAKF and tyrosinase, and this likely supported the better inhibitory behavior of RHAKF. These findings implied RHAKF would be more appropriate to be applied as potential skin-care agent in pharmaceutic or cosmetic industries.