Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

N-Acetylneuraminic acid cytidylyltransferase (EC 2.7.7.43) (CAMP-NeuAc synthetase) from rat liver catalyzes the formation of cytidine monophosphate N-acetylneuraminic acid from CTP and NeuAc. We have purified this enzyme to apparent homogeneity (241-fold) using gel filtration on Sephacryl S-200 and two types of affinity chromatographies (Reactive Brown-10 Agarose and Blue Sepharose CL-6B columns). The pure enzyme, whose amino acid composition and NH2-terminal amino acid sequence are also established, migrates as a single protein band on non-denaturing polyacrylamide gel electrophoresis. The molecular mass of the native enzyme, estimated by gel filtration, was 116 +/- 2 kDa whereas its Mr in sodium dodecyl sulfate-polyacrylamide gel electrophoresis was 58 +/- 1 kDa. CMP-NeuAc synthetase requires Mg2+ for catalysis although this ion can be replaced by Mn2+, Ca2+, or Co2+. The optimal pH was 8.0 in the presence of 10 mM Mg2+ and 5 mM dithiothreitol. The apparent Km for CTP and NeuAc are 1.5 and 1.3 mM, respectively. The enzyme also converts N-glycolylneuraminic acid to its corresponding CMP-sialic acid (Km, 2.6 mM), whereas CMP-NeuAc, high CTP concentrations, and other nucleotides (CDP, CMP, ATP, UTP, GTP, and TTP) inhibited the enzyme to different extents.
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PMID:Purification and characterization of the nuclear cytidine 5'-monophosphate N-acetylneuraminic acid synthetase from rat liver. 157 59

The unstable elevated exposed plus-maze (UEEPM) is a novel model of extreme anxiety which elicits unconditioned flight/escape behaviour in rats. The current studies aimed to investigate further the predictive validity of the paradigm, by examining the effects on UEEPM behaviour of both clinically effective (chronic fluoxetine) and ineffective (acute fluoxetine and chlordiazepoxide) treatments for panic disorder. In the first experiment, male Brown Norway rats received a single injection of fluoxetine (1.0-10.0 mg/kg p.o.) or chlordiazepoxide (CDP, 1.0-10.0 mg/kg i.p.) 30 min prior to UEEPM exposure. In the second experiment, in order to assess the effects of chronic dosing or handling on baseline UEEPM behaviour, subjects received either 21 days vehicle injection (p.o.) or handling, before being exposed to the test. Finally, rats received 21 days fluoxetine (1.0-10.0 mg/kg) in their food, before being tested in the UEEPM. Acute CDP and fluoxetine had no effect on UEEPM behaviour. Chronic handling and vehicle administration (p.o.) significantly reduced escape in the UEEPM, hence preventing the effects of chronic fluoxetine administration from being investigated by p.o. dosing. Chronic fluoxetine in subjects' food (10.0 mg/kg) significantly attenuated animals' propensity to escape from the UEEPM. The results further support the pharmacological similarity between symptoms of panic in humans and escape in the UEEPM and suggest that the UEEPM may represent a paradigm to facilitate investigation into the neurochemical basis of extreme anxiety disorders.
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PMID:Further evidence for the predictive validity of the unstable elevated exposed plus-maze, a behavioural model of extreme anxiety in rats: differential effects of fluoxetine and chlordiazepoxide. 1240 91