Immunochemical analysis of membrane vesicles from Escherichia coli

Abstract

Membrane vesicles isolated from E. coli ML 308-225 were analyzed by crossed immunoelectrophoresis and immunoprecipitates corresponding to the following cellular components were identified: ATPase (EC 3.6.1.3), 2 or 3 NADH dehydrogenases (EC 1.6.99.3), D-lactate dehydrogenase (EC 1.1.1.27), glutamate dehydrogenase (EC 1.4.1.4), dihydro-orotate dehydrogenase (EC 1.3.3.1), 6-phosphogluconate dehydrogenase (EC 1.1.1.43), polynucleotide phosphorylase (EC 2.3.7.8), .beta.-galactosidase (EC 3.2.1.23), lipopolysaccharide and Braun''s lipoprotein. The cellular origin of many of the vesicle immunogens is determined and Braun''s lipoprotein is used as a marker to quantitate the extent of outer membrane contamination (less than 3%). Membrane antigens are also characterized with regard to their amphiphilic or hydrophilic properties by charge-shift crossed immunoelectrophoresis. The following immunogens cross-react with components in membrane vesicles prepared from Salmonella typhimurium: 1 of the three NADH dehydrogenases, ATPase, polynucleotide phosphorylase, 6-phosphogluconate dehydrogenase, Braun''s lipoprotein and 3 unidentified antigens.