Ramaley R, Fujita Y, Freese E
J Biol Chem. 1979 Aug 25;254(16):7684-90.
Inositol 2-dehydrogenase (EC 1.1.1.18) activity appears during growth of Bacillus subtilis (strain 60015) in nutrient sporulation medium. Its synthesis is induced by myo-inositol and repressed by D-glucose. The enzyme has an apparent molecular weight of 155,000 to 160,000 as determined by sucrose density gradient centrifugation, and it is comprised of four subunits, each having a molecular weight of 39,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoelectric point of the enzyme is 4.4 as determined by column isoelectric focusing. The enzyme shows the highest Vmax and lowest Km with myo-inositol as substrate but does not react with scyllo-inositol; it also reacts with the alpha anomer (but not the beta anomer) of D-glucose and with D-xylose. Apparently, the enzyme can remove only the single equatorial hydrogen of the cyclitol or pyranose ring. In contrast to the glucose dehydrogenase of spores, which reacts with D-glucose or 2-deoxy-D-glucose and with NAD or NADP, inositol dehydrogenase requires NAD and does not react with 2-deoxy-D-glucose.
在枯草芽孢杆菌（菌株60015）于营养芽孢形成培养基中生长期间，肌醇2-脱氢酶（EC 1.1.1.18）活性出现。其合成由肌醇诱导，由D-葡萄糖抑制。通过蔗糖密度梯度离心法测定，该酶的表观分子量为155,000至160,000，并且它由四个亚基组成，通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳测定，每个亚基的分子量为39,000。通过柱等电聚焦法测定该酶的等电点为4.4。该酶以肌醇为底物时显示出最高的Vmax和最低的Km，但不与scyllo-肌醇反应；它也与D-葡萄糖的α异头物（但不与β异头物）以及D-木糖反应。显然，该酶只能去除环醇或吡喃糖环的单个赤道氢。与孢子的葡萄糖脱氢酶不同，后者与D-葡萄糖或2-脱氧-D-葡萄糖以及NAD或NADP反应，肌醇脱氢酶需要NAD并且不与2-脱氧-D-葡萄糖反应。
