Role of non-active site residues in maintaining New Delhi metallo-β-lactamase-1(NDM-1) function: an approach of site directed mutagenesis and docking

Abstract

New Delhi metallo-β-lactamase-1(NDM-1) has been known to hydrolyze nearly all β-lactam antibiotics, leading to multi drug resistant state. Hence, it is important to search its structure-function relation to control infections caused by such resistant bacterial strains. Mutagenesis is one of the approaches to explore it. No study has been performed to explore the role of non-active-site residues in the enzyme activity. This study includes mutations of three non-active site residues to comprehend its structure and function simultaneously. Three non-active-site laboratory mutants of NDM-1 were generated by site-directed mutagenesis. The MICs of cefotaxime, cefoxitin,imipenem and meropenem were reduced up to 4 fold for these mutants as compared to wild-type. The hydrolytic activity of mutants was also found to be reduced. Mutants showed a significant change in its secondary structure compared to wild type, as determined by CD spectrophotometer. Catalytic property and stability of these mutants were found to be reduced. Hence it revealed an imperative role of non-active-site residues in the enzymatic activity of NDM-1.

http://bit.ly/2D00kJN