FIG. 1.

Expression and cleavage of glutathione S-transferase-antigen I/II fusion proteins. DNA fragments encoding the N-terminal repetitive domains of SspA, SspB, and SpaP were cloned into pGEX-6P2 and expressed in E. coli. The resulting fusion proteins were purified on glutathione-Sepharose and cleaved with PreScission protease as described in Materials and Methods. The resulting antigen I/II peptides were purified by FPLC on Sephacryl G-75 and evaluated on SDS-10% PAGE gels stained with Coomassie blue. Lanes: 1, SspB/glutathione S-transferase fusion protein; 2, AR-B peptide; 3, AR-P peptide; 4, SspA/glutathione S-transferase fusion protein; 5, AR-A peptide. Positions of molecular size markers are indicated on the left.