| 摘要 |
PROBLEM TO BE SOLVED: To obtain a 1,5-anhydroglucitol (1,5-AG) dehydrogenase capable of simply measuring 1,5-AG in a specimen in high accuracy, extremely useful for diagnosing especially diabetes, etc. SOLUTION: This 1,5-AG dehydrogenase has the following physical and chemical properties. (1) Action: specifically acting on 1,5-AG in the absence of an electron carrier to oxidize a hydroxyl group at the 2-position and to catalyze a reaction to reduce a direct reducing coloring agent. (2) Substrate specificity: strong in 1.5-AG, weak in L-sorbose and somewhat acting on D- glucose. (3) Optimum pH: pH about 8.0-9.0. (4) pH Stability: stable at pH 7.0-9.0. (5) Optimum temperature: at about 35-40 deg.C. (6) Temperature stability: >=90% stable at up to about 40 deg.C. (7) Electron acceptor: capable of using a reducing coloring agent besides 2,6-dichlorophenolindophenol, ferricyanide compound, etc., but incapable of using a coenzyme such as NAD, NADP, etc., and a dissolved enzyme. (8) Molecular weight: about 55,000 (SDS-PACE method). |
