FIG. 6.

SDS-PAGE and immunoblot analysis of the purification of recombinant gonococcal L12 from E. coli BL21 transformed with pGCL12. The Coomassie blue stain of the SDS-PAGE shows: lane 1, whole-cell lysate before IPTG induction; lane 2, whole-cell lysate following IPTG induction; lane 3, soluble proteins following IPTG induction; lane 4, insoluble proteins following IPTG induction; lane 5, nonadsorbed proteins from glutathione-affinity adsorption; lane 6, recombinant gonococcal L12 following thrombin cleavage of GST-GC L12 fusion protein adsorbed onto glutathione-beads. Lane 7 is an immunoblot of a duplicate of lane 6, probed with rabbit α-hCG antiserum. The recombinant gonococcal L12 preparation was judged to be >95% pure.