Dissecting the antigenic mosaic of the Archaebacterium Methanobacterium thermoautotrophicum by monoclonal antibodies of defined molecular specificity

Abstract

The antigenic mosaic of the Archaebacterium Methanobacterium thermoautotrophicum, stain ΔH, was analyzed with a panel of six monoclonal antibodies. Five antigenic determinants were identified. One contains N-acetyl-D-glucosamine, another contains N-acetyl-D-galactosamine, and a third contains γ-glutamylalanine (γ-Glu-Ala). These residues are not involved, at least as immunodominant epitopes, in the other two determinants, one of which contains L-talosaminuronic acid, a component of pseudomurein found only in Methanobacteriaceae. Each of the five determinants was recognized by one monoclonal antibody exclusively. A sixth antibody recognized a structure containing γ-Glu-Ala that could be either a sixth determinant or a subdeterminant within the site already recognized as containing γ-Glu-Ala. We postulate that two of the determinants are strain specific, three are species specific, and one is a common antigen.