FIG. 6.

Immunoblots of the Sus outer membrane proteins separated by electrophoresis on a nondenaturing gel. The resolution of proteins on these gels is poorer than for SDS gels because of the lack of a stacking gel and the high concentration of protein applied to the gel. Membrane proteins and protein complexes were solubilized with 1.5% octyl-glucoside. The 6% polyacrylamide gel and the running buffer contained 0.75% octyl-glucoside to keep the proteins and protein complexes from aggregating nonspecifically. Approximately 600 μg of each membrane fraction was loaded onto each lane. Lane 1, BTΩsusD; lane 3, BTΩsusC(pSDC27); lanes 2 and 4, BTΩsusE(pSGC23A).