兔脾脏β-半乳糖苷酶的异质性。不同形式的分离与特性分析。

Heterogeneity of beta-galactosidase from rabbit spleen. Separation and characterization of different forms.

作者信息

Rodriguez-Berrocal F J, Pérez-González M N, Cabezas J A

出版信息

Enzyme. 1983;30(3):196-204. doi: 10.1159/000469574.

Abstract

Two forms, I and II, of an acid beta-galactosidase from rabbit spleen were separated by DEAE-cellulose chromatography and then characterized. Both forms of the enzyme showed different heat-stability (form I being heat-labile and form II heat-stable), and different pI (6.7 for form I and 5.3 and 6.7 for form II). Their gel filtration patterns were also different: form I was resolved in a single peak of mol. wt. 75,000, whereas form II was resolved in one or two peaks of mol. wt. 120,000 and greater than 200,000, depending on the pH of elution. However, both forms had similar pH stability and behavior toward alpha-methyl-beta-D-galactopyranoside, alpha-methyl-beta-D-glucopyranoside, urea and KCl. Differences in pH optima, optimal temperature and Km values were not marked.

摘要

通过二乙氨基乙基纤维素色谱法分离出兔脾脏酸性β-半乳糖苷酶的两种形式，即形式I和形式II，然后对其进行表征。两种形式的酶表现出不同的热稳定性（形式I对热不稳定，形式II对热稳定），以及不同的等电点（形式I为6.7，形式II为5.3和6.7）。它们的凝胶过滤图谱也不同：形式I在分子量75,000的单峰中分离出来，而形式II根据洗脱pH值在分子量120,000和大于200,000的一个或两个峰中分离出来。然而，两种形式对α-甲基-β-D-吡喃半乳糖苷、α-甲基-β-D-吡喃葡萄糖苷、尿素和氯化钾具有相似的pH稳定性和行为。pH最适值、最适温度和米氏常数的差异并不显著。