文昌鱼酸性磷酸酶在甲醇溶液中的构象与活力变化

文昌鱼酸性磷酸酶（ＡＣＰａｓｅ，Ｅ．Ｃ３．１．３．２）是一种含有铁离子的金属酶，其可见光谱中５００ｎｍ的吸收峰以及荧光５１５ｎｍ的发射峰为该酶分子含铁的特征峰，与酶活力关系密切．通过荧光发射光谱和紫外可见光谱对该酶在不同浓度甲醇溶液中的构象与活力变化进行研究．不同浓度（Ｖ／Ｖ）的甲醇对酶活力有明显的抑制作用，动力学分析表明甲醇对酶的抑制为非竞争性抑制，其抑制常数为２０％．还研究了在甲醇存在下ＡＣＰａｓｅ活力中心的构象与活力变化，结果表明其构象变化快于活力变化．

Changes of Conformation and Activity of ACPase from Branchoistoma belcheri in Methanol Solutions

Branchiostoma belcheri Acid Phosphatase (ACPase, E. C. 3. 1. 3. 2)is a kind of metalloenzyme which exhibits an absorption peak with wevelength at 500 nm and a emission peak with wavelength at 515 urn in its fluorescence spectra because of containing iron. This two character peaks are sensitive to the enzyme activity. The researches about the effect of methanol solution on ACPase were made by means of feuorescence emission and UV-visible spectra. The results showed that the enxyme activity was inhibited distinctly in different concentration(v: v)of methanol solutions. Kinetic analysis of the inhibition shows that the inhibition of methanol on the enxyme is of noncompetitive type and the inhibition constants is found to be 20%. Meanwhile,changes of con formation and activity at the active site of the ACPase has been investigated, and it was found out that the rate constants of denaturation were faster than those of inactivation in the presence of methanol.