Title
Kinetic study of laboratory mutants of NDM-1 metallo-β-lactamase: the importance of an isoleucine at position 35
Author
Francesca Marcoccia, Carlo Bottoni, Alessia Sabatini, Martina Colapietro, Paola Sandra Mercuri, Moreno Galleni, Frédéric Kerff, André Matagne, Giuseppe Celenza, Gianfranco Amicosante, Mariagrazia Perilli
Year
2016
Journal
Antimicrobial Agents and Chemotherapy
Abstract
Two laboratory mutants of NDM-1 were generated by replacing the isoleucine at position 35 with threonine and serine residues: the NDM-1I35T and NDM-1I35Senzymes. These mutants were well characterized, and their kinetic parameters were compared with those of the NDM-1 wild type. The kcat, Km, and kcat/Kmvalues calculated for the two mutants were slightly different from those of the wild-type enzyme. Interestingly, the kcat/Km of NDM-1I35S for loracarbef was about 14-fold higher than that of NDM-1. Far-UV circular dichroism (CD) spectra of NDM-1 and NDM-1I35T and NDM-1I35S enzymes suggest local structural rearrangements in the secondary structure with a marked reduction of α-helix content in the mutants.
Full Article
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Medicinal