Preparation and crossed immunoelectrophoretic analysis of cytoplasmic and outer membrane fractions from Neisseria gonorrhoeae

Abstract

Cell envelopes were obtained from lysates of Neisseria gonorrhoeae, colony type T1, prepared with lysozyme, ethylenediaminetetraacetate, and Brij 58. This preparation was separated into cytoplasmic (inner) and outer membrane fractions by equilibrium sucrose density gradient centrifugation. The former fraction was 10-fold enriched in L-lactate dehydrogenase activity with respect to the latter. On the basis of buoyant density in sucrose, polypeptide patterns in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and enzymatic activity, these preparations appear similar to cytoplasmic and outer membrane preparations from other gram-negative bacteria. The membrane preparations were analyzed by high-resolution crossed immunoelectrophoretic procedures. This technique permitted the identification of antigens originating from the structural components of the gonococcal cell. Among those found to be cytoplasmic membrane components was the fast-moving antigen which occurs widely in gram-negative bacteria.