Antigenic and enzymatic architecture of Micrococcus lysodeikticus membranes established by crossed immunoelectrophoresis.

By crossed immunoelectrophoresis with membrane antiserum, 17 antigens have been detected in fractions from plasma membranes of M. lysodeikticus solubilized with Triton X-100. Absorption tests with protoplasts have demonstrated that eight of the antigens are expressed on the surface. Of these antigens the major one has been identified as a succinylated mannan. Five of the principal immunoprecipitates unaffected by absorption with protoplasts were shown by zymograms to possess the following enzymic activites: succinate dehydrogenase (EC 1.3.99.1), ATPase (EC 3.6.1.3), NADH dehyrogenase (EC 1.6.99.3)(two separate components), and malate dehydrogenase (EC 1.1.1.37). These enzymes or enzyme-complexes are, therefore, not expressed on the outer surface of the protoplast membrane.