Analysis of LAM from M. tuberculosis recombinants carrying mutations in the proline motif.
M. tuberculosis strains carrying the indicated embCMtb alleles were constructed by gene switching. LAM was analyzed in recombinant strains grown on agar. A, periodic acid-Schiff staining. B, Western blotting using antibody CS-35. M. smegmatis embCΔ is complemented with wild-type embCMtb (lane 1), embCMtb N638A (lane 2), embCMtb N638A (lane 3), embCMtb N652A (lane 4), and markers (lane M). The expected range for migration of LAM and LM is shown for the periodic acid-Schiff-stained gel. The Western blot detects only LAM.