Schüte H, Flossdorf J, Sahm H, Kula M R
Eur J Biochem. 1976 Feb 2;62(1):151-60. doi: 10.1111/j.1432-1033.1976.tb10108.x.
Formaldehyde hydrogenase and formate dehydrogenase were purified 130-fold and 19-fold respectively from Candida boidinii grown on methanol. The final enzyme preparations were homogenous as judged by acrylamide gel electrophoresis and by sedimentation in an ultracentrifuge. The molecular weights of the enzymes were determined by sedimentation equilibrium studies and calculated as 80000 and 74000 respectively. Dissociation into subunits was observed by treatment with sodium dodecylsulfate. The molecular weights of the polypeptide chains were estimated to be 40000 and 36000 respectively. The NAD-linked formaldehyde dehydrogenase specifically requires reduced glutathione for activity. Besides formaldehyde only methylglyoxal served as a substrate but no other aldehyde tested. The Km values were found to be 0.25 mM for formaldehyde, 1.2 mM for methylglyoxal, 0.09 mM for NAD and 0.13 mM for glutathione. Evidence is presented which demonstrates that the reaction product of the formaldehyde-dehydrogenase-catalyzed oxidation of formaldehyde is S-formylglutathione rather than formate. The NAD-linked formate dehydrogenase catalyzes specifically the oxidation of formate to carbon dioxide. The Km values were found to be 13 mM for formate and 0.09 mM for NAD.
从以甲醇为碳源生长的博伊丁假丝酵母中分别纯化出甲醛脱氢酶和甲酸脱氢酶，纯化倍数分别为130倍和19倍。通过丙烯酰胺凝胶电泳和超速离心沉降判断，最终的酶制剂是均一的。通过沉降平衡研究测定酶的分子量，分别计算为80000和74000。用十二烷基硫酸钠处理可观察到酶解离成亚基。多肽链的分子量估计分别为40000和36000。与NAD相关的甲醛脱氢酶的活性特别需要还原型谷胱甘肽。除甲醛外，只有甲基乙二醛可作为底物，而测试的其他醛都不行。甲醛的Km值为0.25 mM，甲基乙二醛为1.2 mM，NAD为0.09 mM，谷胱甘肽为0.13 mM。有证据表明，甲醛脱氢酶催化甲醛氧化的反应产物是S-甲酰谷胱甘肽而不是甲酸。与NAD相关的甲酸脱氢酶特异性催化甲酸氧化成二氧化碳。甲酸的Km值为13 mM，NAD为0.09 mM。
