Conformational sampling, catalysis, and evolution of the bacterial phosphotriesterase.

ABSTRACT: To efficiently catalyze a chemical reaction, enzymes are required to maintain fast rates for formation of the Michaelis complex, the chemical reaction and product release. These distinct demands could be satisfied via fluctuation between different conformational substates (CSs) with unique configurations and catalytic properties. However, there is debate as to how these rapid conformational changes, or dynamics, exactly affect catalysis. As a model system, we have studied bacterial phosphotriesterase (PTE), which catalyzes the hydrolysis of the pesticide paraoxon at rates limited by a physical barrier-either substrate diffusion or conformational change. The mechanism of paraoxon hydrolysis is understood in detail and is based on a single, dominant, enzyme conformation. However, the other a

SUBMITTER: Jackson CJ 

PROVIDER: S-EPMC2799856 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature