scholarly journals A Radical on the Met-Tyr-Trp Modification Required for Catalase Activity in Catalase-Peroxidase Is Established by Isotopic Labeling and Site-Directed Mutagenesis

2010 ◽  
Vol 132 (24) ◽  
pp. 8268-8269 ◽  
Author(s):  
Xiangbo Zhao ◽  
Javier Suarez ◽  
Abdelahad Khajo ◽  
Shengwei Yu ◽  
Leonid Metlitsky ◽  
...  
Keyword(s):  
Catalase Activity ◽  
Isotopic Labeling ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Catalase Peroxidase

Modulation of the Activities of Catalase−Peroxidase HPI ofEscherichia coliby Site-Directed Mutagenesis†

Biochemistry ◽  
2000 ◽  
Vol 39 (19) ◽  
pp. 5868-5875 ◽  
Author(s):  
Alex Hillar ◽  
Brian Peters ◽  
Ryan Pauls ◽  
Alexander Loboda ◽  
Haoming Zhang ◽  
...  
Keyword(s):  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Catalase Peroxidase

Probing the function of Mycobacterium tuberculosis catalase-peroxidase by site-directed mutagenesis

2005 ◽  
pp. 3495 ◽  
Author(s):  
Nigel A. J. Eady ◽  
Jesmin ◽  
Spiros Servos ◽  
Anthony E. G. Cass ◽  
Judit M. Nagy ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Catalase Peroxidase

scholarly journals Use of site-directed mutagenesis to probe the structure, function and isoniazid activation of the catalase/peroxidase, KatG, from Mycobacterium tuberculosis

1999 ◽  
Vol 338 (3) ◽  
pp. 753 ◽  
Author(s):  
Brigitte SAINT-JOANIS ◽  
Hélène SOUCHON ◽  
Martin WILMING ◽  
Kai JOHNSSON ◽  
Pedro M. ALZARI ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Structure Function ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Catalase Peroxidase

scholarly journals Use of site-directed mutagenesis to probe the structure, function and isoniazid activation of the catalase/peroxidase, KatG, from Mycobacterium tuberculosis

1999 ◽  
Vol 338 (3) ◽  
pp. 753-760 ◽  
Author(s):  
Brigitte SAINT-JOANIS ◽  
Hélène SOUCHON ◽  
Martin WILMING ◽  
Kai JOHNSSON ◽  
Pedro M. ALZARI ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Acyl Carrier Protein ◽  
Site Directed Mutagenesis ◽  
Single Amino Acid ◽  
Directed Mutagenesis ◽  
Reduction Activity ◽  
Nitroblue Tetrazolium Reduction ◽  
Catalase Peroxidase ◽  
Tetrazolium Reduction

A series of mutants bearing single amino acid substitutions often encountered in the catalase/peroxidase, KatG, from isoniazid-resistant isolates of Mycobacterium tuberculosis has been produced by site-directed mutagenesis. The resultant enzymes were overexpressed, purified and characterized. Replacing Cys-20 by Ser abolished disulphide-bridge formation, but did not affect either dimerization of the enzyme or catalysis. The substitution of Thr-275, which is probably involved in electron transfer from the haem, by proline resulted in a highly unstable enzyme with insignificant enzyme activities. The most commonly occurring substitution in drug-resistant clinical isolates is the replacement of Ser-315 by Thr; this lowered catalase and peroxidase activities by 50% and caused a significant decrease in the KatG-mediated inhibition of the activity of the NADH-dependent enoyl-[acyl-carrier protein] reductase, InhA, in vitro. The ability of this enzyme to produce free radicals from isoniazid was severely impaired, as judged by its loss of NitroBlue Tetrazolium reduction activity. Replacement of Leu-587 by Pro resulted in marked instability of KatG, indicating that the C-terminal domain is also important for structural and functional integrity.

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