Catalase activity of wild-type and mutant KatG, KatG-mediated INH-converting activity, and INH susceptibility

Recombinant KatGaCatalase activityKatG-mediated INH-converting activitybINH susceptibilityc
kcat (S−1)Km (mM)kcat/Km ratio (mutant/wild type)
Wild type2,403 ± 44060.1 ± 9.51.00+S
A245V*2,666 ± 53062.8 ± 10.81.06+S
G297V*188 ± 3668.7 ± 7.00.07R
L48Q*-R463L1,776 ± 31064.8 ± 12.50.69+R
R463L2543 ± 45064.0 ± 11.01.01+S
L390 (CTA) insertion*NDNDNAR
  • a *, novel mutation.

  • b Time courses of net KatG-mediated INH conversion are shown in Fig. 2C.

  • c INH susceptibilities shown are those of M. tuberculosis H37Rv strains having the katG gene of the wild type and those of clinical strains having the katG gene with the respective mutation(s). S, susceptible; R, resistant.

  • d ND, not detected.

  • e NA, not applicable.