【作者】 门华涛；

【导师】 罗文鸿；

【作者基本信息】 汕头大学 ， 生物化学与分子生物学， 2008， 硕士

【摘要】 背景与目的:血浆中含有氨基脲敏感型胺氧化酶(semicarbazide-sensitive amine oxidase,SSAO)。本研究的目的是纯化兔血浆中的SSAO蛋白,并以甲胺为底物研究兔血浆中具有SSAO酶活性的蛋白组分的酶动力学参数。材料与方法:利用DEAE-琼脂糖FF凝胶柱层析分离兔血浆蛋白,测定各收集组分的SSAO酶活性;以甲胺为底物测定SSAO酶动力学参数。结果:从兔血浆蛋白中分离得到两个具有SSAO酶活性的蛋白组分A和B。以甲胺为底物,未处理的血浆SSAO的酶动力学参数Km=1.83±0.13 mmol/L,Vmax=0.12±0.003 nmol/min/mg。蛋白组分B的酶动力学参数Km值(2.05±0.43 mmol/L)小于蛋白组分A的Km值(3.14±0.63 mmol/L)。组分B的酶动力学参数Vmax值(1.46±0.10 nmol/min/mg)小于组分A的Vmax值(2.85±0.20 nmol/min/mg)。结论:兔血浆含有两种SSAO酶组分,均可以催化甲胺氧化脱氨生成甲醛;组分A、B动力学特征有所不同。更多还原

【Abstract】 BACKGROUND AND AIM: To purify and investigate enzyme kinetic properties of rabbit plasma semicarbazide-sensitive amine oxidases (SSAO), using methylamine as substrate. MATERIALS AND METHODS: Formaldehyde, an oxidative deamination product of methylamine, was examined by HPLC analysis. Rabbit plasma SSAO was purified by chromatography with DEDE-sepharose FF (eluted with 30 mmol/L and then 100 mmol/L sodium phosphate buffers, all at pH 7.0), then assayed and Michaelis-Menten analyzed. RESULTS: Two kinds of SSAOs (labeled as peak A and peak B) had been obtained, which were catalytically active with methylamine as substrate. The kinetic parameters Km and Vmax of plasma were 1.83±0.13 mmol/L and 22.20±0.48 nmol/min/mg, respectively. The Km of peak B (2.05±0.43 mmol/L) was lower than that of peak A (3.14±0.63 mmol/L), the Vmax of the peak A (1.03±0.07 nmol/min/mg) was lower than that of peak B (2.52±0.17 nmol/min/mg). CONCLUSION: In rabbit plasma, there are two kinds of SSAO which can catalyze methylamine into formaldehyde and have significantly different kinetic parameters.更多还原