Catalytic promiscuity in the alpha/beta-hydrolase superfamily: Hydroxamic acid formation, C-C bondformation, ester and thioester hydrolysis in the C-C hydrolase family
Li, C. (Chen), Hassler, Melanie and Bugg, Tim. (2008) Catalytic promiscuity in the alpha/beta-hydrolase superfamily: Hydroxamic acid formation, C-C bondformation, ester and thioester hydrolysis in the C-C hydrolase family. Chembiochem, Vol.9 (No.1). pp. 71-76. ISSN 1439-4227Full text not available from this repository.
Official URL: http://dx.doi.org/10.1002/cbic.200700428
The haloperoxidase family of alpha/beta-hydrolases contains enzymes of several different catalytic activities, including esterases, C-C hydrolases and cofactor-independent haloperoxidases (perhydrolases), but the molecular basis of this catalytic promiscuity is not fully understood. The C-C hydrolase enzyme MhpC from E. coli is shown to possess esterase and thioesterase activity, and the ability to activate hydroxylamine as a nucleophile to form hydroxamic acid products. The ratio of these activities was examined for nine site-directed mutant enzymes that contained mutations at nonessential residues in the enzyme active site. Higher levels of esterase and thioesterase activity were found in mutants Phe173Gly and Trp264Gly; this might be due to increased amounts of space in the active site. Higher levels of hydroxamic acid formation activity were found in mutant Asn109His-a mutation found in many haloperoxidase enzymes. Wild-type and mutant MhpC enzymes were also capable of C-C bond formation in organic solvents, and the highest activity was observed in nonpolar solvents. The results provide experimental support for the catalytic promiscuity shown in this family of enzymes, and indicate that differences in catalytic function can be introduced by point mutations.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry
Q Science > QP Physiology
|Divisions:||Faculty of Science > Chemistry|
|Library of Congress Subject Headings (LCSH):||Hydrolase, Hydrolysis, Esterases, Catalysis|
|Journal or Publication Title:||Chembiochem|
|Publisher:||Wiley - V C H Verlag GmbH & Co. KGaA|
|Official Date:||4 January 2008|
|Number of Pages:||6|
|Page Range:||pp. 71-76|
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