Causes of the Production of Multiple Forms of β-Galactosidase by Bacillus circulans
Causes of the Production of Multiple Forms of β-Galactosidase by Bacillus circulans
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DOI：
10.1271/bbb.100574
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发表时间：
2011-02-01
影响因子：
1.6
通讯作者：
Nakanishi, Kazuhiro
中科院分区：
文献类型：
--
作者：
Song, Jingyuan;Abe, Kiriko;Nakanishi, Kazuhiro
研究了来自环状芽孢杆菌ATCC 31382的商业酶制剂中多种类型的β-半乳糖苷酶的存在及其转半乳糖基化活性的差异。分离并鉴定了四种免疫同源的β-半乳糖苷酶，即β-Gal-A、β-Gal-B、β-Gal-C和β-Gal-D。所有的酶的N-末端氨基酸序列是相同的，生化特性是相似的，除了低聚半乳糖生产。β-Gal-B、β-Gal-C和β-Gal-D主要以20-30和9- 12%的最大产率产生三糖和四糖，而β-Gal-A以5%乳糖作为底物产生7%的三糖。除β-Gal-A外，所有酶的Lineweaver-Burk图均显示出双相行为。通过用从B的培养液中分离的蛋白酶处理，将β-Gal-A截短以产生多种β-半乳糖苷酶。circulans.用胰蛋白酶处理β-Gal-A产生了由21-kDa和70-kDa蛋白质组成的活性91-kDa蛋白质，其特征与β-Gal-D相似。
The presence of multiple types of beta-galactosidases in a commercial enzyme preparation from Bacillus circulans ATCC 31382 and differences in their transgalactosylation activity were investigated. Four beta-galactosidases, beta-Gal-A, beta-Gal-B, beta-Gal-C, and beta-Gal-D, which were immunologically homologous, were isolated and characterized. The N-terminal amino acid sequences of all of the enzymes were identical and biochemical characteristics were similar, except for galactooligosaccharide production. beta-Gal-B, beta-Gal-C, and beta-Gal-D produced mainly tri- and tetra saccharides at maximum yields of 20-30 and 9-12%, while beta-Gal-A produced trisaccharide with 7% with 5% lactose as substrate. The Lineweaver-Burk plots for all of the enzymes, except for beta-Gal-A, showed biphasic behavior. beta-Gal-A was truncated to yield multiple beta-galactosidases by treatment with protease isolated from the culture broth of B. circulans. Treatment of beta-Gal-A with trypsin yielded an active 91-kDa protein composed of 21-kDa and 70-kDa proteins with characteristics similar to those for beta-Gal-D.