FIG. 1.

Purification and metabolic radiolabeling of the recombinant 27-kDa antigen in E. coli and expression of the native form in BCG and M. tuberculosis. E. coli SG13009 cells harboring the plasmid pRHB27 were grown to an OD₆₀₀ of 0.7 with or without [³H]palmitic acid. Protein production was induced by IPTG. The induced protein was purified using a nickel-nitrilotriacetic acid column, and samples were analyzed by SDS-PAGE and stained with Coomassie blue. The radioactively labeled samples were exposed to an X-ray film for 1 month. Numbers at the left indicate molecular masses in kilodaltons. Lane A, SDS-PAGE of the purified recombinant 27-kDa lipoprotein; lane B, an autoradiogram of the purified radiolabeled 27-kDa lipoprotein after SDS-PAGE analysis; lanes C and D, Western blot of BCG and M. tuberculosis H37Rv lysates, respectively, exposed to rabbit-anti-27-kDa serum; lane E, RT-PCR of the LprG gene in HeLa cells transfected with pIHB27 (1), pRHB27 as a control vector (2), and λ HindIII DNA marker (m).