Identification of a Reactive Cysteine Residue at the Glutamine Binding Site of Carbamyl Phosphate Synthetase
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چکیده
منابع مشابه
Identification of a reactive cysteine residue at the glutamine binding site of carbamyl phosphate synthetase.
Carbamyl phosphate synthetase from Escherichia coli, which is composed of a light and a heavy subunit, is inhibited with respect to its glutamine-dependent reactions by treatment with ~-2-amino-4-oxo-5-chloro[5-‘~C]pentanoic acid. This glutamine analog reacts with a glutamineor albizziinprotectable site on the light subunit to yield an enzyme covalently linked to a 4-oxo[W]norvaline moiety. The...
متن کاملFunctional arginyl residues as ATP binding sites of glutamine synthetase and carbamyl phosphate synthetase.
The reaction of phenylglyoxal with two enzymes in which ATP plays a complex role has been studied. Both ovine brain glutamine synthetase and Escherichia coli carbamyl phosphate synthetase [carbamoyl-phosphate synthase (glutamine); ATP:carbamate phosphotransferase (dephosphorylating, amido-transferring); EC 2.7.2.9]were inactivated by phenylglyoxal. The specificity of this reagent for arginyl re...
متن کاملA Kinetic Study of Carbamyl Phosphate Synthetase.
While it is clear from the stoichiometry of the over-all reaction (Reaction 3) that 2 moles of ATP are utilized per mole of carbamyl phosphate formed (l), equilibrium dialysis experiments indicated that only 1 mole of ATP was bound per mole of enzyme in the absence of acetylglutamate (2). In order to gain more information about the nature of ATP binding by carbamyl phosphate synthetase, kinetic...
متن کاملCarbonic-phosphoric anhydride (carboxy phosphate). Significance in catalysis and regulation of glutamine-dependent carbamyl phosphate synthetase.
Carbonic-phosphoric anhydride (carboxy phosphate) is formed on the enzyme when glutamine-dependent carbamyl phosphate synthetase (Escherichia coli) is incubated with ATP, Mg’+, and HCO,,-. Carboxy phosphate may be trapped by borohydride reduction to formate and as the trimethyl derivative by treatment with diazomethane. The rate of enzyme-bound carboxy phosphate formation is evidently extremely...
متن کاملRat liver glutamine synthetase. Preparation, properties, and mechanism of inhibition by carbamyl phosphate.
Glutamine synthetase, purified from rat liver, is homogeneous on acrylamide gel electrophoresis and on ultracentrifugation (~20,~) 15.0 S). The enzyme, which consists of eight subunits (subunit molecular weight, 44,000), resembles ovine brain glutamine synthetase in its physical properties, amino acid composition, and substrate specificity. Complete inhibition of the liver enzyme by methionine ...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1972
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(19)44772-8