Murein-lipoprotein of Escherichia coli: A protein involved in the stabilization of bacterial cell envelope

摘要: Two independent mutants of Escherichia coli lacking murein-lipoprotein have been found. One mutant whose mutation was named lpo subjected to detailed analyses. The absence both found and unbound lipoproteins shown by electrophoretic analysis 14C-arginine labelled membrane proteins the mutant. Nor serologically cross-reacting material detected in Ouchterlony-method. Sequestering magnesium from cell suspensions ethylenediaminetetraacetic acid caused lysis, which prevented presence 0.5 M sucrose. Incubation culture media at a very low level resulted formation blebs Examination cells electron microscopy showed that outer uneven with small irregular protuberances, some pinched off forming vesicles various sizes. Phosphotungstate used for negative-staining penetrated into periplasmic space cells. leaked considerable fraction their enzymes. These physiological morphological alterations lipoproteinless suggest helps maintain envelope structure connecting murein so may fulfil its functions as barrier environment.