Kinetic isotope effects for alkaline phosphatase reactions: implications for the role of active-site metal ions in catalysis.

ABSTRACT: Enzyme-catalyzed phosphoryl transfer reactions have frequently been suggested to proceed through transition states that are altered from their solution counterparts, with the alterations presumably arising from interactions with active-site functional groups. In particular, the phosphate monoester hydrolysis reaction catalyzed by Escherichia coli alkaline phosphatase (AP) has been the subject of intensive scrutiny. Recent linear free energy relationship (LFER) studies suggest that AP catalyzes phosphate monoester hydrolysis through a loose transition state, similar to that in solution. To gain further insight into the nature of the transition state and active-site interactions, we have determined kinetic isotope effects (KIEs) for AP-catalyzed hydrolysis reactions with several phosphate mo

SUBMITTER: Zalatan JG 

PROVIDER: S-EPMC3171187 | biostudies-literature | 2007 Aug

REPOSITORIES: biostudies-literature