Westerlund B, Kuusela P, Risteli J, Risteli L, Vartio T, Rauvala H, Virkola R, Korhonen T K
Department of General Microbiology, University of Helsinki, Finland.
Mol Microbiol. 1989 Mar;3(3):329-37. doi: 10.1111/j.1365-2958.1989.tb00178.x.
Interaction of the basement-membrane binding O75X adhesin of uropathogenic Escherichia coli with various extracellular matrix proteins was studied. The adhesin showed strong binding to type IV collagen immobilized on microtitre plates, whereas other collagens, laminin and fibronectin, were only weakly recognized. Similarly, specific binding of [125I]-labelled type IV collagen to O75X-positive bacteria was shown. Interaction of the two proteins was also demonstrated by affinity chromatography of the O75X adhesin on immobilized type IV collagen. The adhesin bound strongly to the immobilized N-terminal 7S domain of type IV collagen, and the binding of [125I]-labelled type IV collagen to O75X-positive bacteria was inhibited by the soluble 7S domain. Binding of O75X to type IV collagen and to its 7S domain was specifically inhibited by chloramphenicol but was not affected by periodate or endoglycosidase-H treatment of the glycoproteins. Our results show that the 7S domain of type IV collagen is the basement membrane receptor for the O75X adhesin and suggest an interaction based on protein-protein recognition. Inhibition of the interaction by chloramphenicol favours the supposition that a modified tyrosine is involved in the binding site.
研究了致病性大肠杆菌的基底膜结合性O75X黏附素与各种细胞外基质蛋白的相互作用。该黏附素与固定在微量滴定板上的IV型胶原表现出强烈结合，而其他胶原、层粘连蛋白和纤连蛋白仅被微弱识别。同样，显示了[125I]标记的IV型胶原与O75X阳性细菌的特异性结合。通过将O75X黏附素在固定化IV型胶原上进行亲和层析，也证明了这两种蛋白的相互作用。该黏附素与固定化的IV型胶原N端7S结构域强烈结合，可溶性7S结构域可抑制[125I]标记的IV型胶原与O75X阳性细菌的结合。氯霉素可特异性抑制O75X与IV型胶原及其7S结构域的结合，但高碘酸盐或糖苷内切酶-H对糖蛋白的处理对其无影响。我们的结果表明，IV型胶原的7S结构域是O75X黏附素的基底膜受体，并提示基于蛋白质-蛋白质识别的相互作用。氯霉素对这种相互作用的抑制支持了这样一种假设，即修饰的酪氨酸参与了结合位点。
