人血浆乙酰水杨酸酯酶动力学特性研究

Study on Enzyme Kinetics of Aspirin Esterase in Chinese Human Plasma

目的研究中国成年人血浆乙酰水杨酸酯酶的酶动力学特性。方法应用反相HPLC测定培养体系中乙酰水杨酸(ASA)及其主要代谢物水杨酸(SA)的含量,以SA/(ASA+SA)的比值来表示乙酰水杨酸酯酶的活性。结果乙酰水杨酸酯酶的米氏常数Km=429.67nmol·L-1和Vmax=2.56mmol·min-1·L-1(血浆),最佳反应温度为37℃,培养缓冲液pH为7.4。结论该方法灵敏度高、简便、快速、可靠,该酶对pH的变化较敏感,对热极不稳定。

OBJECTIVE To develop a method for the study of aspirin esterase kinetics in Chinese adult human plasma. METHODS The concentrations of aspirin（ASA）and its metabolites （salicylic acid,SA） were determined by reversed phase HPLC and the aspirin esterase activity was assessed by SA/（ASA＋SA）.RESULTS The enzyme kinetics analysis revealed that Vmax and Km were 2.56 mmol·min-1·L^-1 （plasma） and 429.67 nmol·L^-1, respectively. The optimal reaction temperature and pH were 37 ℃ and 7.4, respectively. CONCLUSION The method is simple, specific and reliable, aspirin esterase was sensitive to pH value and heat.