- Substrate and stereochemical specificity of the organophosphorus acid anhydrolase from Alteromonas sp. JD6.5 toward p-nitrophenyl phosphotriesters
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The enzyme OPAA hydrolyzes p-nitrophenyl phosphotriesters bearing substituents at the phosphorus center ranging in size from methyl to phenyl. The enzyme exhibits stereoselectivity toward the hydrolysis of chiral substrates with a preference for the S(P)
- Hill, Craig M.,Wu, Feiyue,Cheng, Tu-Chen,Defrank, Joseph J.,Raushel, Frank M.
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p. 1285 - 1288
(2007/10/03)
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- Mg2+-Promoted P-O vs. S-O Bond Cleavage in the Alcoholyses of Phenyl Phosphatosulfate
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In order to obtain insight into the selectivity of Mg2+ at the site of bond cleavage of P-O and S-O of the P-O-S linkage, metal ion-promoted alcoholyses of phenyl phosphatosulfate were studied.Mg2+ quantitatively promoted P-O bond cleavage in the methanolysis, but mixed cleavage of the P-O bond, which occurred partly due to hydrolysis by trace water and the S-O bond in the reaction of ethanol, 1- or 2-propanol.The ratio of the S-O bond cleavage against the mixed cleavage increased in a order EtOH (11.5percent) 2+ and Zn2+ promoted selective P-O and S-O bond cleavage, respectively, in the reaction of 2-propanol as well as methanolysis.The medium-dependent change in the selectivity of Mg2+ at the site of bond cleavage was discussed.
- Eiki, Toshio,Negishi, Shin-ichi,Izumi, Mitsunori,Ishida, Naoko,Hada, Hiroshi
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p. 2931 - 2935
(2007/10/02)
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