Cross-linking analysis of the outer membrane proteins of Neisseria gonorrhoeae

The organization of outer membrane proteins of Neisseria gonorrhoeae was investigated by using two-dimensional dodecyl sulfate-polyacrylamide gel electrophoresis and cross-linking agents. A naturally occurring protein aggregate, which may be composed of two proteins of 50,000 molecular weight, was detected in all strains. Treatment of whole cells with cross-linking agents yielded several additional complexes, suggesting that other proteins are arranged in the outer membrane as near neighbors. The principal outer membrane protein (molecular weight, 34,000) cross-linked (i) to itself to form a complex whch appeared to be trimeric, (ii) to the 28,000-molecular-weight outer membrane protein to form a bimolecular comlex, and (iii) to the 28,000-molecular-weight outer membrane protein in a 3:1 ratio. The formation of these complexes was independent of (i) colony type, (ii) colony opacity, (iii) pH during growth, and (iv) presence of markers for drug resistance or hypersensitivity.