Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.1.49 (phosphoenolpyruvate carboxykinase)
 4,654 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acyclovir diphosphate (acyclo-GDP) is a metabolite of the antiviral drug acyclovir [9-(2-hydroxyethoxymethyl)guanine]. Seven enzymes capable of catalyzing the phosphorylation of GDP and dGDP (nucleoside diphosphate kinase, pyruvate kinase, creatine kinase, phosphoglycerate kinase, succinyl-CoA synthetase, phosphoenolpyruvate carboxykinase and adenylosuccinate synthetase) also catalyzed the phosphorylation of acyclo-GDP. In general, acyclo-GDP had a lower V'max and a higher K'm than either GDP or dGDP. None of these enzymes showed significantly higher rates of phosphorylation with GDP or acyclo-GDP in herpes simplex virus-infected Vero cells as compared to uninfected Vero cells. The contribution of each enzyme to the phosphorylation of acyclo-GDP in vivo was estimated from the kinetic data from the partially purified enzymes, the level of each enzyme in Vero cells, and the physiological concentrations of both substrates and inhibitors. The relative order of estimated rates of acyclo-GDP phosphorylation in Vero cells was phosphoglycerate kinase much greater than pyruvate kinase greater than phosphoenolpyruvate carboxykinase greater than nucleoside diphosphate kinase greater than succinyl-CoA synthetase greater than creatine kinase greater than adenylosuccinate synthetase. The calculated potential for acyclo-GDP phosphorylation by these enzymes was adequate to account for the amounts of acyclo-GTP formed in cell culture.
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PMID:Phosphorylation of acyclovir diphosphate by cellular enzymes. 715 65

Biochemical and metabolic data lead to the conclusion that the enzyme phosphoenolpyruvate carboxykinase (PEPCK) contributes to a critical point of divergence in energy conservation pathways between mammals and nematodes. The Ascaris suum PEPCK shares considerable homology with PEPCK from avian liver and is a good candidate for mutagenesis studies. The Cys306 substitution by Ser and Ala produced active enzymes and the two mutants are kinetically indistinguishable from each other. This substitution affects the catalytic affinity for the formation of the specific enzyme-nucleotide complex (k(cat)/K(m)) in the forward and reverse reactions. Studies with the substrate analogs 2(')dGDP and 2(')dGTP indicate that Cys306 in A. suum PEPCK is one of the residues important in nucleotide binding and may interact with the 2(')OH group in the ribose ring. Alternatively, mutation of this residue could cause protein changes that interfere with the proper conformation of the nucleotides for optimal catalysis to take place.
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PMID:Role of cysteine 306 in the catalytic mechanism of Ascaris suum phosphoenolpyruvate carboxykinase. 1212 66