Native TprC and TprI are amphiphilic but tethered to the peptidoglycan sacculus, whereas TprF is entirely periplasmic and tightly bound.
A, extensively washed Triton X-114-insoluble material visualized in negatively stained whole mounts by transmission electron microscopy. Triton X-114 phase partitioning of T. pallidum lysates (1 × 109 organisms) without (−) or with (+) presolubilization with 2% DDM. Whole cells (WC), Triton X-114-insoluble material (Ins), and aqueous and Triton X-114-enriched phases (Aq and Det, respectively) were separated by SDS-PAGE followed by immunoblotting using antisera directed against TprCSp (B), TprISp (C), or TprI/FSp (D). Arrowheads in D, TprF. Molecular mass markers (kDa) are shown at the left of each immunoblot.