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.

蛋白质的水解可以产生更多的生物活性部分。为了获得更多的生物活性，木瓜种子蛋白被木瓜蛋白酶水解以产生生物肽。经过超滤，凝胶过滤色谱和反相高效液相色谱纯化后，成功制备了两种新型肽。应用基质辅助激光解吸/电离飞行时间/飞行时间（MALDI-TOF-TOF）串联质谱仪鉴定了这两种纯化肽的氨基酸序列，它们分别是天冬酰胺-酪氨酸-精氨酸-精氨酸-谷氨酸（NYRRE，737.059 Da）和精氨酸-组氨酸-丙氨酸-赖氨酸-苯丙氨酸（RHAKF，658.010 Da）。在抗氧化剂分析中，RHAKF显示出更强的DPPH，超氧化物阴离子自由基的清除活性和脂质过氧化抑制作用均优于NYRRE。此外，RHAKF的IC具有比NYRRE更好的铜螯合活性。₅₀值为0.93 mg / mL，低于NYRRE（2.11 mg / mL）。酪氨酸酶抑制评估表明，RHAKF的抑制活性比NYRRE好得多。为了解释这种现象，使用分子对接模拟来揭示酪氨酸酶和肽之间的相互作用。在RHAKF和酪氨酸酶之间观察到更多的对接位点，这可能支持了RHAKF更好的抑制行为。这些发现暗示RHAKF将更适合在制药或化妆品行业用作潜在的皮肤护理剂。