GALACTOSE-BINDING SITE IN ESCHERICHIA-COLI HEAT-LABILE ENTEROTOXIN (LT) AND CHOLERA-TOXIN (CT)
GALACTOSE-BINDING SITE IN ESCHERICHIA-COLI HEAT-LABILE ENTEROTOXIN (LT) AND CHOLERA-TOXIN (CT)
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DOI：
10.1111/j.1365-2958.1994.tb00467.x
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发表时间：
1994-08-01
影响因子：
3.6
通讯作者：
HOL, WGJ
中科院分区：
文献类型：
--
作者：
MERRITT, EA;SIXMA, TK;HOL, WGJ
霍乱毒素以及与之密切相关的大肠杆菌不耐热肠毒素（LT）中的半乳糖结合位点，是合理设计潜在抗霍乱药物的一个有吸引力的靶点。在本文中，我们分析了在几个晶体结构中所看到的这个结合位点的分子结构，包括我们在此报道的分辨率为2.2埃的LT - 半乳糖复合物的结构。游离毒素上的结合表面包含几个紧密结合的水分子以及一个由B亚基的51 - 60位残基组成的相对灵活的环。在受体结合过程中，这个环通过与神经节苷脂GM1五糖以及一组稳定毒素 - 受体复合物的水分子共同形成氢键而变得紧密有序。
The galactose-binding site in cholera toxin and the closely related heat-labile enterotoxin (LT) from Escherichia coli is an attractive target for the rational design of potential anti-cholera drugs. In this paper we analyse the molecular structure of this binding site as seen in several crystal structures, including that of an LT:galactose complex which we report here at 2.2 Angstrom resolution. The binding surface on the free toxin contains several tightly associated water molecules and a relatively flexible loop consisting of residues 51-60 of the B subunit. During receptor binding this loop becomes tightly ordered by forming hydrogen bonds jointly to the G(M1) pentasaccharide and to a set of water molecules which stabilize the toxin:receptor complex.