Isolation of Diphosphopyridine Nucleotide-dependent L-Fucose Dehydrogenase from Pork Liver

作者：Harry Schachter, J Sarney, Edward J. McGuire, Saul Roseman · 发表于：Journal of Biological Chemistry · 年份：1969 · DOI：10.1016/s0021-9258(18)93693-8 · 被引用次数：79 · 研究领域：Diet, Metabolism, and Disease、Digestive system and related health、Amino Acid Enzymes and Metabolism

A DPN+-dependent L-fucose dehydrogenase has been isolated from pork liver and purified over 300-fold by a combination of ammonium sulfate fractionation, diethylaminoethyl cellulose chromatography, gel filtration on Sephadex G-100, and preparative polyacrylamide gel electrophoresis.The pH optimum for the dehydrogenase was 8.7 and K,,, values were 2.0 x 10d5 M for DPN+ and 3.2 x 10m4 M for L-fucose.The immediate product of L-fucose oxidation was shown to be L-fuconolactone (probably the l--f 5 isomer); the lactone was hydrolyzed spontaneously to Lfuconate at the pH of the reaction.The purified enzyme also catalyzed the oxidation of L-galactose (Km 8.0 x lOMa M), n-arabinose (Km, 2.1 X 1O-a M), and 3-amino-3-deoxy-Darabinose (Km, 8.0 x 10ea M); all active sugars have the same hydroxyl group configurations from C-2 to C-4.The 2-, 3-, or 4-epimers of D-arabinose were much less effective substrates for the enzyme (K, > 3 X 10m2 M).