Physics Commons^™

Mechanistic Studies On The Mononuclear ZnIi-Containing Metallo-Β-Lactamase Imis From Aeromonas Sobria, Narayan Sharma, Christine E. Hajdin, Sowmya Chandrasekar, Brian Bennett, Ke-Wu Yang, Michael W. Crowder

Physics Faculty Research and Publications

In an effort to understand the reaction mechanism of a B2 metallo-β-lactamase, steady-state and pre-steady-state kinetic and rapid freeze quench electron paramagnetic resonance (EPR) studies were conducted on ImiS and its reaction with imipenem and meropenem. pH dependence studies revealed no inflection points in the pH range of 5.0−8.5, while proton inventories demonstrated at least 1 rate-limiting proton transfer. Site-directed mutagenesis studies revealed that Lys224 plays a catalytic role in ImiS, while the side chain of Asn233 does not play a role in binding or catalysis. Stopped-flow fluorescence studies on ImiS, which monitor changes in tryptophan fluorescence on the enzyme, …