PDF(Pubmed)
Abstract：
TolC is the outer membrane protein responsible for antibiotic efflux in E. coli. Compared to other outer membrane proteins it has an unusual fold and has been shown to fold independently of commonly used periplasmic chaperones, SurA and Skp. Here we find that the assembly of TolC involves the formation of two folded intermediates using circular dichroism, gel electrophoresis, site-specific disulfide bond formation and radioactive labeling. First the TolC monomer folds, and then TolC assembles into a trimer both in detergent-free buffer and in the presence of detergent micelles. We find that a TolC trimer also forms in the periplasm and is present in the periplasm before it inserts in the outer membrane. The monomeric and trimeric folding intermediates may be used in the future to develop a new approach to antibiotic efflux pump inhibition by targeting the assembly pathway of TolC.
摘要：
TolC是在大肠杆菌中负责抗生素外排的外膜蛋白。与其他外膜蛋白相比，它具有不寻常的折叠，并且已显示出独立于常用的周质伴侣的折叠，苏拉和Skp.在这里，我们发现TolC的组装涉及使用圆二色性形成两个折叠中间体，凝胶电泳,位点特异性二硫键形成和放射性标记。首先TolC单体折叠，然后TolC在无洗涤剂缓冲液和洗涤剂胶束存在下组装成三聚体。我们发现TolC三聚体也在周质中形成，并在插入外膜之前存在于周质中。未来可能会使用单体和三聚体折叠中间体通过靶向TolC的组装途径来开发抗生素外排泵抑制的新方法。
