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Purification and properties of the phosphotriesterase from Pseudomonas diminuta.
The phosphotriesterase produced from the opd cistron of Pseudomonas diminuta was purified 1500-fold to homogeneity using a combination of gel filtration, ion exchange, hydrophobic, and dye matrixExpand
Structural and catalytic diversity within the amidohydrolase superfamily.
The amidohydrolase superfamily comprises a remarkable set of enzymes that catalyze the hydrolysis of a wide range of substrates bearing amide or ester functional groups at carbon and phosphorusExpand
Molecular structure of dihydroorotase: a paradigm for catalysis through the use of a binuclear metal center.
From the three-dimensional structures of the enzyme-bound substrate and product, it has been possible to propose a unique catalytic mechanism for dihydroorotase, and strikingly, in subunit II, carbamoyl L-aspartate is observed binding near the binuclear metal center with its carboxylate side chain ligating the two metals and thus displacing the bridging hydroxide ion. Expand
Structure of carbamoyl phosphate synthetase: a journey of 96 A from substrate to product.
The two halves of the large subunit are related by a nearly exact 2-fold rotational axis, thus suggesting that this polypeptide chain evolved from a homodimeric precursor. Expand
Characterization of the zinc binding site of bacterial phosphotriesterase.
Protection against inactivation by metal chelation was afforded by the binding of competitive inhibitors, suggesting that at least one metal is at or near the active site. Expand
Mechanism for the hydrolysis of organophosphates by the bacterial phosphotriesterase.
A mechanism for the hydrolysis of organophosphates by the bacterial PTE has been proposed and is consistent with the existence of a proton relay from Asp301 to His254 to Asp233 that is used to ferry protons away from the active site with substrates that do not require activation of the leaving group phenol. Expand
Three-dimensional structure of the zinc-containing phosphotriesterase with the bound substrate analog diethyl 4-methylbenzylphosphonate.
The position of the inhibitor within the active site suggests that the nucleophile for the hydrolysis reaction is the metal-bound hydroxide, and this most likely explains the broad substrate specificity exhibited by phosphotriesterase. Expand
High resolution X-ray structures of different metal-substituted forms of phosphotriesterase from Pseudomonas diminuta.
By measuring the anomalous X-ray data from crystals of the Zn(2+)/Cd(2-)-species, it has been possible to determine that the alpha-metal ion is zinc and the beta-site is occupied by cadmium. Expand
The Binding of Substrate Analogs to Phosphotriesterase*
The three-dimensional structure of PTE complexed with the inhibitor diisopropyl methyl phosphonate, which serves as a mimic for sarin is described and the structure of the enzyme complexing with triethyl phosphate is presented. Expand
Three-dimensional structure of phosphotriesterase: an enzyme capable of detoxifying organophosphate nerve agents.
The molecular model of phosphotriesterase presented here provides the initial structural framework necessary toward understanding the enzyme's broad substrate specificities and its catalytic mechanism. Expand