No abstract available

[en] A number of the major pathogen-specific immunogens of Treponema pallidum were characterized recently as amphiphilic, integral membrane proteins by phase partitioning with Triton X-114. In the present study, we demonstrated that the same membrane immunogens (designated as detergent phase proteins [DPPs]) become radiolabeled upon in vitro incubation of T. pallidum with various ³H-labeled fatty acids. Radioimmunoprecipitation with a monoclonal antibody confirmed that the ³H-labeled 47-kilodalton protein corresponded to the well-characterized treponemal antigen with the identical apparent molecular mass. Failure to detect ³H-labeled DPPs following incubation with erythromycin confirmed that protein acylation required de novo protein synthesis by the bacteria. When treponemes were incubated with [³H]myristate, [³H]palmitate, or [³H]oleate, radiolabeled proteins corresponding to the DPPs were detected upon autoradiography. Demonstration that a number of the abundant membrane immunogens of T. pallidum are proteolipids provides information to help clarify their membrane association(s) and may serve to explain their extraordinary immunogenicity