产肠毒素大肠杆菌产生的不耐热肠毒素游离A亚基的检测与纯化。

Detection and purification of the free A subunit of heat-labile enterotoxin produced by enterotoxigenic Escherichia coli.

作者信息

Tsuji T, Honda T, Miwatani T, Miyama A

机构信息

Department of Microbiology, Fujita Health University School of Medicine, Toyoake Aichi, Japan.

出版信息

FEMS Microbiol Lett. 1991 Jan 15;61(2-3):277-82. doi: 10.1016/0378-1097(91)90565-r.

DOI:10.1016/0378-1097(91)90565-r

PMID:1903752

Abstract

After removal of total B subunit and heat-labile enterotoxin (LT) from crude cell extracts of enterotoxigenic Escherichia coli (HB 101-EWD 299) by Bio-gel A 5 m column chromatography, the crude cell extract was shown to contain a free A subunit (A' subunit) that did not bind to the coligenoid of the B subunits. The A' subunit was found to be immunologically identical to the A subunit of holo-LT and was purified to show only one band in SDS-poly-acrylamide gel electrophoresis (PAGE). The mobility of the A' subunit was identical to that of the A subunit of holo-LT. The pI value of the A' subunit was also the same as that of the A subunit of holo-LT. These data suggest that in enterotoxigenic E. coli there is free A subunit which may be involved in formation of holo-LT, analogously to free B subunit (coligenoid), and that the free A subunit is physicochemically and immunologically identical to the A subunit of holo-LT.

摘要

通过Bio-gel A 5m柱色谱法从产肠毒素大肠杆菌（HB 101-EWD 299）的粗细胞提取物中去除总B亚基和热不稳定肠毒素（LT）后，发现粗细胞提取物中含有一种游离A亚基（A'亚基），它不与B亚基的类大肠杆菌素结合。发现A'亚基在免疫学上与全毒素LT的A亚基相同，并经纯化后在SDS-聚丙烯酰胺凝胶电泳（PAGE）中仅显示一条带。A'亚基的迁移率与全毒素LT的A亚基相同。A'亚基的pI值也与全毒素LT的A亚基相同。这些数据表明，在产肠毒素大肠杆菌中存在游离A亚基，它可能与全毒素LT的形成有关，类似于游离B亚基（类大肠杆菌素），并且游离A亚基在物理化学和免疫学上与全毒素LT的A亚基相同。