Kinetic mechanism of choline kinase from rat striata.
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چکیده
منابع مشابه
Purification and characterization of choline/ethanolamine kinase from rat liver.
Choline kinase, the first enzyme in the CDP-choline pathway for phosphatidylcholine biosynthesis, was purified 26,000-fold from rat liver to a specific activity of 143,000 nmol.min-1.mg-1 protein. The subunit molecular mass was 47 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, while the apparent native molecular mass was 160 kDa by size exclusion chromatography, suggesting a ...
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Both choline kinase and ethanolamine kinase are present in the cytosol of nerve endings prepared from rat brain are the products of their action, phosphocholine (84 nmol/g fresh wt. of brain) and phosphoethanolamine (190 nmol/g fresh wt. of brain). In contrast with the enzymes from the cytosol of whole brain, both are as equally active at pH 7.5 as 9.0. Determination of kinase activity in membr...
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Choline kinase was purified approximately 300-fold, in 5% yield, from an autolysate of dried brewers’ yeast. A molecular weight of 67,000 was estimated using a Stokes radius of 33 A, as determined by Sephadex G-200 chromatography. An s~,,,~ of 4.8 S was obtained by sucrose density gradient centrifugation. Enzyme activity was diminished by sulfhydryl inhibitors and stabilized by the presence of ...
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The localization, purification, and some enzymatic properties of choline acetyltransferase from rat brain were studied. Most assays were performed with a specific radiometric micromethod. Solubilization of the enzyme was examined after homogenization of cerebral cortices by means which disintegrate nerve endings. In isotonic KC1 the enzyme was recovered in solution. In more dilute KC1 the enzym...
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Initial velocity patterns for human placental choline acetyltransferase show a series of converging lines for both the forward and reverse reaction; with Kacetyl coenzyme A = 11.9 micron, Kcholine = 0.41 mM, KCOA = 8.8 micron, and Kacetylcholine = 1.3 mM. The relative rates of acetylcholine synthesis (Vf) to acetylcholine breakdown (Vr) is 4.5. Product inhibition by acetylcholine is competitive...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1984
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(17)42811-0