长白山白眉蝮蛇蛇毒精氨酸酯酶1的研究Ⅱ.酶学性质和荧光光谱研究(续Ⅰ)

Studies on the Arginine Esterase l in Chinese Agkistrodon Blomhoffii Ussurensis Venom Ⅱ.Enzymatic Characteristics and Fluorescence Properties

测得了长白山白眉蝮蛇毒精氨酸酯酶 1的最适反应的pH范围为 7.0～ 8.0 ,且与酶反应底物对甲苯磺酰-L -精氨酸甲酯 (TAME)的反应无明显的最适应反应温度 .荧光光谱的研究结果表明 :该酶的酪氨酸残基的荧光被色氨酸残基的荧光所掩盖 ;同步荧光光谱结果表明 :当发射波长与激发波长差Δλ分别为 2 0nm和 75nm时 ,精氨酸酯酶 1的荧光光谱分别由酪氨酸 (Tyr)和色氨酸 (Trp)残基所贡献 ,且处于亲水性环境中 ;精氨酸酯酶 1的荧光发射强度受溶液酸度变化的影响 .I- ,Acr和NBS对精氨酸酯酶 1的荧光淬灭结果表明这种酶中含有多个色氨酸残基 ,且处于不同的微环境中。

In this paper,we obtained the optimal pH for the arginine esterase 1 isolated from Chinese Agkistodon blomhoffii Ussurensis venom in the range from 7.0 to 8.0.And this kind of enzyme didn't show sensitivity towards the change of temperature.The fluorescence of the Tyr residues were overlapped by that of the Trp residues.When the Δλ were 20 nm and 75 nm,the fluorescence of arginine esterase 1 were mainly contributed by its Tyr and Trp residues,respectively.And the fluorescence intensity of the enzyme was affected by the change of the pH of the solutions.The fluorescence quenching effects of I -,Acr and NBS on the arginine esterase showed that several Trp residues were contained in this enzyme and situated in different microenvironments.