Rotman B, Ellis J H
J Bacteriol. 1972 Sep;111(3):791-6. doi: 10.1128/jb.111.3.791-796.1972.
A galactose-binding protein related to the mglP transport system of Escherichia coli increases its affinity and binding capacity for the substrate when exposed to both d-galactose and specific antibodies. For this increase to occur, the binding protein has to be in contact with d-galactose for at least 2 min prior to the addition of the antibodies. This reaction was used to show that other substrates of the mglP transport system compete with galactose for a site(s) of the binding protein and that the degree of competition is comparable to that observed in vivo. A model for substrate translocation is presented postulating a cellular component that can induce conformational changes in the galactose-binding protein similar to those caused by antibodies.
一种与大肠杆菌mglP转运系统相关的半乳糖结合蛋白，在同时暴露于D-半乳糖和特异性抗体时，会提高其对底物的亲和力和结合能力。为了使这种增加发生，结合蛋白必须在添加抗体之前与D-半乳糖接触至少2分钟。该反应被用于表明mglP转运系统的其他底物与半乳糖竞争结合蛋白的一个或多个位点，并且竞争程度与体内观察到的相当。本文提出了一种底物转运模型，假定存在一种细胞成分，它能诱导半乳糖结合蛋白发生类似于抗体引起的构象变化。
