Elucidation of the reaction mechanism of the Metalo-beta-Lactamase NDM-1

PALACIOS, A.R.; LLARRULL, L.I.; VILA, A.J.

Villa Carlos Paz

Congreso; XLII Reunion Anual de la Sociedad Argentina de Biofisica; 2013

Sociedad Argentina de Biofisica

Carbapenems comprise the latest generation of beta-lactam antibiotics and are used as antibiotics of last resort to treat infections caused by most â-lactam-resistant bacteria. beta-lactamases, the enzymes that inactivate these antibiotics, can be classified into Serin-beta-lactamases or Metalo-beta-lactamases (MBLs) and this last class could be subdivided into B1, B2 and B3 subclasses. In spite of the fact that carbapenems have a structure that renders them highly resistant to most beta-lactamases, an emerging class of beta-lactamases can act against them. In particular, NDM-1 is a B1 MBL with a broad substrate spectrum and the carbapenemase activity of NDM-1 is of great clinical concern(1). In previous works, our group identified a reaction intermediate in the hydrolysis of carbapenems by BcII, another B1 MBL(2), and our unpublished results indicate that this intermediate is common to all three MBL subclasses. Here we report the steady and pre-steady state kinetics of NDM-1 (both native and Co(II)-substituted) and the reaction mechanism of the hydrolysis of imipenem. We have confirmed the presence of the characterized reaction intermediate in NDM-1, this information is the cornerstone for the rational design of a common MBL inhibitor. Acknowledgements: ANPCyT, NIH, CONICET 1- Mckenna M., Nature, 2013, 394. 2- Tioni M. F. et al., J. Am. Chem. Soc., 2008, 15852.