Kcat for the hydrolysis of chlorpyrifos by organophosphorous hydrolase

Value 73.8 sec^-1 Range: Table - link sec^-1
Organism Bacteria Escherichia coli
Reference Cho CM, Mulchandani A, Chen W. Altering the substrate specificity of organophosphorus hydrolase for enhanced hydrolysis of chlorpyrifos. Appl Environ Microbiol. 2004 Aug70(8):4681-5. p.4683 table 1 and left column 2nd paragraphPubMed ID15294802
Method Directed evolution. Researchers used two rounds of DNA shuffling and screened about 12,000 mutants to improve the hydrolytic activity of an organophosphorus hydrolase (OPH) 725-fold toward the toxin chlorpyrifos.
Comments "Although the values for the wild-type OPH were somewhat different than those reported previously (Dumas et al 1989 PMID 2555328 reported a Kcat of 2100 s^-1 for organophosphorous hydrolase from Pseudomonas diminuta), the measured kcat of 73.8 s^-1 and Km of 0.26 mM were consistent with the poorly hydrolyzable nature of chlorpyrifos."
Entered by Uri M
ID 105433