牦牛骨胶原蛋白肽对酪氨酸酶的抑制作用

Inhibition of Tyrosinase by Yak Collagen Peptides

摘要:

为探究牦牛骨胶原蛋白多肽组分YBCP-2-2对酪氨酸酶的抑制方式，对其进行了抗氧化活性、Cu2+螯合能力、肽对酪氨酸单酚酶和二酚酶抑制动力学及酪氨酸酶荧光光谱影响等方面的分析。结果表明YBCP-2-2具有显著抗氧化能力，DPPH自由基和ABTS+自由基的清除IC50分别为6.02 mg/mL和0.81 mg/mL，总还原力在8.00 mg/mL时吸光值达0.57，铜离子螯合能力也较为出色，IC50为3.22 mg/mL。YBCP-2-2对酪氨酸单酚酶具有明显迟滞效应并呈质量浓度依赖性，当抑制物质量浓度达到20.00 mg/mL时，反应初速度从0.012 /min下降至0.003 9 /min；对酪氨酸二酚酶的抑制类型为混合竞争性抑制，Vmax和Km均随胶原蛋白肽质量浓度的变化而改变，抑制常数KI为0.58 mg/mL。YBCP-2-2能与酪氨酸酶发生相互作用导致酶蛋白荧光猝灭且引起荧光光谱从340.20 nm红移至351.60 nm。结果证明了胶原蛋白多肽具有较强的酪氨酸酶抑制活性，为完善肽类对酪氨酸酶抑制作用的理论研究提供了理论依据。

Abstract:

To investigate the inhibition mode of the yak bone collagen peptide fraction, YBCP-2-2, its antioxidant activity, Cu2+ chelating capacity, inhibition kinetics against tyrosine mono- and di-phenolase, and interaction with tyrosinase were analyzed using fluorescence spectroscopy. The results demonstrated that YBCP-2-2 exhibited notable antioxidant capacity, with IC50 values of 6.02 mg/mL and 0.81 mg/mL for scavenging DPPH and ABTS free radicals, respectively. YBCP-2-2 also exhibited a total reducing power absorbance value of 0.57 at 8.00 mg/mL, along with superior Cu2+ chelating capacity, with an IC50 of 3.22 mg/mL. Furthermore, YBCP-2-2 substantially inhibited tyrosine monophenolase in a mass concentration-dependent manner. At an inhibitor mass concentration of 20.00 mg/mL, the initial velocity of the reaction decreased from 0.012 /min to 0.003 9 /min. The inhibition type on tyrosine diphenolase was identified as mixed competitive inhibition, with both Vmax and Km undergoing changes in response to variations in the collagen peptide mass concentration; the inhibition constant KI was determined as 0.58 mg/mL. The interaction between YBCP-2-2 and tyrosinase induced fluorescence quenching of the enzyme, accompanied by a red-shift in the fluorescence emission spectrum from 340.20 nm to 351.60 nm. These findings conclusively demonstrate the potent tyrosinase inhibitory activity of collagen peptides, thereby providing a theoretical foundation for further investigations into peptide-based tyrosinase inhibition.