| 摘要 |
PROBLEM TO BE SOLVED: To obtain a new kinase, having high substrate specificity for 1,5- anhydroglucitol (1,5-AG), capable of phosphorylating the 1,5-AG in the presence of nucleoside diphosphates and Mg ions and useful for the measurement, etc., of the 1,5-AG with a high accuracy. SOLUTION: This new ADP-dependent hexokinase has higher substrate specificity for 1,5-anhydroglucitol (1,5-AG) than that in the case of using glucose as a substrate, is capable of catalyzing a reaction for substituting hydroxyl group at the 6-position of the 1,5-AG with phosphate group in the presence of nucleoside diphosphates and magnesium ions and producing 1,5-anhydroglucitol phosphate and nucleoside monphosphates, is used for simply measuring the 1,5-AG with a high accuracy and is useful for diagnosis, etc., of diabetes by measuring the amount of the 1,5-AG in blood plasma. The enzyme is obtained by culturing a strain of Thermococcus litoralis ATCC51850 in a culture medium at 95 deg.C for 20 hr, then separating and crushing the microbial cell and extracting and purifying an active fraction from the resultant crushed liquid of the microbial cell. |
