产肠毒素大肠杆菌产生的热不稳定肠毒素B亚基的结晶及初步X射线衍射研究

Crystallization and preliminary X-ray diffraction study of the heat-labile enterotoxin B subunit produced by enterotoxigenic Escherichia coli.

作者信息

Tsuji T, Fukuyama K, Matsubara H, Honda T, Miwatani T

机构信息

Department of Bacteriology and Serology, Osaka University, Japan.

出版信息

J Mol Biol. 1989 Jul 5;208(1):207-8. doi: 10.1016/0022-2836(89)90097-1.

DOI:10.1016/0022-2836(89)90097-1

PMID:2671385

Abstract

Heat-labile enterotoxin LT produced by enterotoxigenic Escherichia coli is composed of A and B subunits. The A subunit is enzymatically active; whereas, through the action of the B subunit, the toxin binds to the receptor, a GM1 ganglioside present on the cell surface. Crystals of the LT-B subunit were formed at room temperature by vapor diffusion with polyethylene glycol in the presence of the non-ionic detergent beta-octylglucoside. The crystals were characterized by X-radiation as orthorhombic, space group P2(1)2(1)2(1), with unit cell dimensions of a = 224.1 A, b = 65.3 A, c = 118.4 A. They diffract X-rays to a resolution of at least 2.5 A and are stable to X-rays.

摘要

产肠毒素大肠杆菌产生的热不稳定肠毒素LT由A和B亚基组成。A亚基具有酶活性；而通过B亚基的作用，毒素与细胞表面存在的受体GM1神经节苷脂结合。LT-B亚基的晶体在室温下通过在非离子去污剂β-辛基葡糖苷存在下与聚乙二醇进行气相扩散而形成。这些晶体经X射线表征为正交晶系，空间群P2(1)2(1)2(1)，晶胞尺寸为a = 224.1 Å，b = 65.3 Å，c = 118.4 Å。它们对X射线的衍射分辨率至少为2.5 Å，并且对X射线稳定。