STUDIES ON GLUCOSE DEHYDROGENASE OF ASPERGILLUS ORYZAE .3. GENERAL ENZYMATIC PROPERTIES
STUDIES ON GLUCOSE DEHYDROGENASE OF ASPERGILLUS ORYZAE .3. GENERAL ENZYMATIC PROPERTIES
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DOI：
10.1016/0005-2744(67)90218-5
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发表时间：
1967-01-01
期刊：
影响因子：
--
通讯作者：
BAK, TG
中科院分区：
文献类型：
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作者：
BAK, TG
高纯度的葡萄糖脱氢酶可以催化d -葡萄糖、2-脱氧-d -葡萄糖、d -木糖、d -果糖和d -甘露糖被某些氧化还原染料如2,6-氯酚苯酚（DCIP）和醌如[β]-萘醌氧化。分子氧也可以作为受体，尽管速度极慢。d -葡萄糖的氧化产物为d -葡萄糖-8-内酯。DCIP对葡萄糖的氧化作用在pH 6.5和45℃时达到最大。d -葡萄糖和DCIP的表观Km值分别为0.025 M和0.1 mM。动力学研究排除了三元配合物参与酶的催化作用。酶与葡萄糖的分光光度滴定没有给出在催化过程中黄素半醌形成的任何指示。葡萄糖脱氢的酶被证明是不可逆的，因为葡萄糖-[δ] -内酯不能再氧化酶的还原黄素。
Glucose dehydrogenase, highly purified, from Aspergillus oryzae catalyzed the oxidation of D-glucose, 2-deoxy-D-glucose, D-xylose, D-fructose, and D-mannose by certain redox dyes such as 2,6-dlchloro-phenollndophenol (DCIP) and qulnones such as [beta]-naphthoquinone. Molecular oxygen could also be utilized as acceptor, though at an extremely slow rate. The oxidation product of D-glucose was identified as D-glucono-8-lactone. The oxidation of glucose by DCIP was maximal at pH 6.5 and 45[degree]. The apparent Km values for D-glucose and DCIP were 0.025 M arid 0.1 mM, respectively. Kinetic studies ruled out the involvement of a ternary complex in the enzyme catalysis. Spectro-photometrlc titration of the enzyme with glucose did not give any indication of the formation of flavin semiqulnone during the catalysis. The dehydrogenatlon of glucose by the enzyme was shown to be Irreversible, since glucono-[delta] -lactone failed to reoxldlze the reduced flavin of the enzyme.