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Mutation of katG in a clinical isolate of mycobacterium tuberculosis: Effects on catalase-peroxidase for isoniazid activation
Purkana, Ihsanawatib, Natalia D.b, Syah Y.M.b, Retnoningrum D.S.b, Kusuma H.S.c
a Biochemistry Research Division, Department of Chemistry, Faculty of Sciences and Technology, Airlangga University, Surabaya, Indonesia
b Biochemistry Research Division, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Bandung, Indonesia
c Department of Chemical Engineering, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
[vc_row][vc_column][vc_row_inner][vc_column_inner][vc_separator css=”.vc_custom_1624529070653{padding-top: 30px !important;padding-bottom: 30px !important;}”][/vc_column_inner][/vc_row_inner][vc_row_inner layout=”boxed”][vc_column_inner width=”3/4″ css=”.vc_custom_1624695412187{border-right-width: 1px !important;border-right-color: #dddddd !important;border-right-style: solid !important;border-radius: 1px !important;}”][vc_empty_space][megatron_heading title=”Abstract” size=”size-sm” text_align=”text-left”][vc_column_text]© 2016, Ukrainian Biochemical Journal. All rights reserved.Mutations in katG gene are often associated with isoniazid (INH) resistance in Mycobacterium tuberculosis strain. This research was perfomed to identify the katG mutation in clinical isolate (L8) that is resistant to INH at 1 μg/ml. In addition to characterize the catalase-peroxidase of KatG L8 and perform the ab initio structural study of the protein to get a more complete understanding in drug activation and the resistance mechanism. The katG gene was cloned and expressed in Escherichia coli, then followed by characterization of catalase-peroxidase of KatG. The structure modelling was performed to know a basis of alterations in enzyme activity. A substitution of A713G that correspond to Asn238Ser replacement was found in the L8 katG. The Asn238Ser modification leads to a decline in the activity of catalase-peroxidase and INH oxidation of the L8 KatG protein. The catalytic efficiency (Kcat/KM) of mutant KatGAsn238Serrespectively decreases to 41 and 52% for catalase and peroxidase. The mutant KatGAsn238Seralso shows a decrease of 62% in INH oxidation if compared to a wild type KatG (KatGwt). The mutant Asn238Ser might cause instability in the substrate bindingsite of KatG, because of removal of a salt bridge connecting the amine group of Asn238 to the carboxyl group of Glu233, which presents in KatGwt. The lost of the salt bridge in the substrate binding site in mutant KatGAsn238Sercreated changes unfavorable for enzyme activities, which in turn emerge as INH resistance in the L8 isolate of M. tuberculosis.[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Author keywords” size=”size-sm” text_align=”text-left”][vc_column_text]Amino Acid Substitution,Antitubercular Agents,Bacterial Proteins,Base Sequence,Catalase,Catalytic Domain,Cloning, Molecular,Drug Resistance, Bacterial,Escherichia coli,Gene Expression,Genetic Vectors,Humans,Isoniazid,Kinetics,Models, Molecular,Mutation,Mycobacterium tuberculosis,Protein Binding,Protein Conformation, alpha-Helical,Protein Conformation, beta-Strand,Protein Interaction Domains and Motifs,Recombinant Proteins,Sequence Alignment,Substrate Specificity,Tuberculosis, Pulmonary[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Indexed keywords” size=”size-sm” text_align=”text-left”][vc_column_text]Catalase-peroxidase,INH resistance,KatG,Mycobacterium tuberculosis[/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”Funding details” size=”size-sm” text_align=”text-left”][vc_column_text][/vc_column_text][vc_empty_space][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][vc_empty_space][megatron_heading title=”DOI” size=”size-sm” text_align=”text-left”][vc_column_text]https://doi.org/10.15407/ubj88.05.071[/vc_column_text][/vc_column_inner][vc_column_inner width=”1/4″][vc_column_text]Widget Plumx[/vc_column_text][/vc_column_inner][/vc_row_inner][/vc_column][/vc_row][vc_row][vc_column][vc_separator css=”.vc_custom_1624528584150{padding-top: 25px !important;padding-bottom: 25px !important;}”][/vc_column][/vc_row]