The Outer Cell-Wall Membrane of Pseudomonas aeruginosa

Abstract

The cell-wall outer membranes of strains of Pseudomonas aeruginosa of seven different immunotypes were isolated as a native complex by mild shear and centrifugation. The native complex consisted of polysaccharide, protein, lipopolysaccharide, and lipid components. Some contaminating peptidoglycan material was identified. Protein was separated from lipopolysaccharide by solubilization of the native complex followed by chromatography on a Sephadex G-I00 column. Analysis of protein components by electrophoresis on polyacrylamide gel showed that most of the strains contained at least five protein bands varying from 18,000 daltons to 100,000 daltons in molecular weight. Immunologic specificity of the native complex was examined by radioimmunoassay against rabbit antisera. Each antiserum reacted to the highest titer with the homologous native complex, but cross-reactions of various degrees occurred with antisera to other immunotypes of Pseudomonas. When a pyocin inhibition assay was used, lipopolysaccharide was shown to have specific pyocin-receptor activity.