A comparison of the catalytic properties of cellobiose:quinone oxidoreductase and cellobiose oxidase from Phanerochaete chrysosporium.
A comparison of the catalytic properties of cellobiose:quinone oxidoreductase and cellobiose oxidase from Phanerochaete chrysosporium.
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纤维二糖：醌氧化还原酶和金孢原毛平革菌纤维二糖氧化酶催化特性的比较。
DOI：
10.1111/j.1432-1033.1992.tb17026.x
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
K. Eriksson
中科院分区：
文献类型：
--
作者：
M. Samejima;K. Eriksson
对 FAD 酶纤维二糖：醌氧化还原酶 (CBQ) 和血红素/FAD 酶、纤维二糖氧化酶 (CBO) 的几种催化特性进行了研究和比较。发现二氯酚-靛酚是两种酶氧化纤维二糖的非常好的电子受体。对于这两种酶，观察到以二氯酚-靛酚作为共底物进行氧化的最佳 pH 值约为 4。该反应的营业额也非常相似。纤维二糖氧化的 Km 值相同，而 CBO 与二氯酚-靛酚的 Km 低于 CBQ。大气中的氧气对于CBO和CBQ来说都是非常差的电子受体，但是CBO可以利用细胞色素c作为有效的电子受体，而CBQ则不能。因此，CBO 对细胞色素 c 的比活性比氧高约 200 倍。因此，区分这两种酶的一种方法是通过 CBO 的细胞色素 c 还原能力。因此，我们建议将CBO的命名暂时改为纤维二糖：细胞色素c氧化还原酶，直到可以安装合理的名称为止。两种酶都具有自由基还原活性。源自 1,2,4,5-四甲氧基苯的阳离子自由基被两种酶以几乎相同的反应速率还原。木质素过氧化物酶催化乙酰丁香酮氧化产生的苯氧自由基也被这两种酶还原。由酚氧化酶（木质素过氧化物酶以及漆酶）形成的苯氧自由基的减少对于防止再聚合反应可能很重要，我们认为这将显着促进木质素降解。
Several catalytic properties of the FAD enzyme cellobiose:quinone oxidoreductase (CBQ) and the heme/FAD enzyme, cellobiose oxidase (CBO) have been investigated and compared. Dichlorophenol-indophenol was found to be a very good electron acceptor for cellobiose oxidation by both enzymes. The optimal pH value for this oxidation with dichlorophenol-indophenol as a co-substrate was observed around pH 4 for both enzymes. The turnover numbers of this reaction were also very similar. The Km values for cellobiose oxidation were identical, whereas the Km for CBO with dichlorophenol-indophenol is lower than that of CBQ. Atmospheric oxygen is a very poor electron acceptor for both CBO and CBQ, however, CBO can utilize cytochrome c as an effective electron acceptor, while CBQ cannot. The specific activity of CBO for cytochrome c is thus about 200-times higher than for oxygen. Thus, one way to distinguish the two enzymes is by the cytochrome-c-reducing ability of CBO. Therefore, we propose that the nomenclature for CBO is tentatively changed to cellobiose:cytochrome c oxidoreductase until a rational name can be installed. Both enzymes have radical-reducing activities. The cation radical, derived from 1,2,4,5-tetramethoxybenzene, was reduced by both enzymes at almost the same reaction rate. The phenoxyradical produced by lignin peroxidase, catalyzing the oxidation of acetosyringon, was also reduced by both enzymes. The reduction of phenoxyradicals formed by phenoloxidases (lignin peroxidases, as well as laccases) may be important in preventing repolymerization reactions which we suggest would significantly facilitate lignin degradation.
木质酶介导的苯氧基自由基形成和聚合不受纤维二糖：醌氧化还原酶的影响。
影响因子：
3.9
作者：
Odier,E;Mozuch,MD;Kalyanaraman,B;Kirk,TK
通讯作者：
Kirk,TK