Gariépy J, Schoolnik G K
Proc Natl Acad Sci U S A. 1986 Jan;83(2):483-7. doi: 10.1073/pnas.83.2.483.
The Escherichia coli heat-stable enterotoxin, STIb was prepared by solid-phase peptide synthesis and purified to homogeneity by high-pressure liquid chromatography. This analogue was iodinated and shown to bind specifically to rat intestinal membranes. The radiolabeled peptide was derivatized at the amino terminus with the photoreactive heterobifunctional crosslinking agent N-hydroxysuccinimidyl p-benzoylbenzoate. This photoreactive probe also exhibited binding specificity. It was mixed with rat intestinal brush border membranes and photolyzed in the presence or absence of excess unlabeled STIb. Polyacrylamide gel electrophoresis performed in the presence of sodium dodecyl sulfate and 2-mercaptoethanol indicated that the peptide probe was crosslinked specifically to two molecular species of 57 and 75 kDa. One or both of these molecules appear to constitute the enterotoxin receptor or to be in close proximity to it.
大肠杆菌热稳定肠毒素STIb通过固相肽合成制备，并通过高压液相色谱纯化至同质。该类似物经碘化后显示能特异性结合大鼠肠膜。放射性标记的肽在氨基末端用光反应性异双功能交联剂对苯甲酰苯甲酸N-羟基琥珀酰亚胺酯进行衍生化。这种光反应性探针也表现出结合特异性。它与大鼠肠刷状缘膜混合，并在有或没有过量未标记STIb的情况下进行光解。在十二烷基硫酸钠和2-巯基乙醇存在下进行的聚丙烯酰胺凝胶电泳表明，肽探针与57 kDa和75 kDa的两种分子物种特异性交联。这些分子中的一个或两个似乎构成肠毒素受体或与之紧密相邻。
