Regulation of dehydrogenases/one-electron transferases by modification of flavin redox potentials. Effect of product binding on semiquinone stabilization in yeast flavocytochrome b2.
Regulation of dehydrogenases/one-electron transferases by modification of flavin redox potentials. Effect of product binding on semiquinone stabilization in yeast flavocytochrome b2.
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通过改变黄素氧化还原电位来调节脱氢酶/单电子转移酶。
DOI：
10.1111/j.1432-1033.1986.tb09516.x
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
F. Labeyrie
中科院分区：
文献类型：
--
作者：
M. Tegoni;J. Janot;F. Labeyrie
在室温下，在存在和不存在丙酮酸（生理反应产物）的情况下，对Hansenula异常l -乳酸细胞色素c氧化还原酶（或黄细胞色素b2）进行厌氧滴定时，进行了光谱和电位测量。在相同的条件下，通过电子顺磁共振测量，估算了黄素的光谱贡献，并直接测定了黄酮类半醌的比例。在本研究中，我们展示了黄素自由基在18℃下的可见光吸收和顺磁特性，以及丙酮酸对黄素各单电子偶对氧化还原电位的显著影响。在丙酮酸存在下，半醌形式的热力学稳定被解释为黄细胞色素b2活性的一种调节模式。考虑到类似的控制已被观察到属于这类脱氢酶/单电子转移酶的另外两种黄酮酶，我们认为氧化还原电位调节可能是一种有效的调节类型，其中半醌是专性中间体。
Spectroscopic and potentiometric measurements have been carried out, at room temperature, during anaerobic titrations of Hansenula anomala L-lactate cytochrome c oxidoreductase (or flavocytochrome b2) both in the presence and in the absence of pyruvate (the physiological reaction product). Under the same conditions, the flavin spectral contribution was estimated and the flavosemiquinone proportion was directly determined by electron paramagnetic resonance measurements. In the present study, we show the visible light absorption and paramagnetic characteristics of the flavin radical at 18 degrees C and also the dramatic effect of pyruvate on the redox potential of each monoelectronic couple of the flavin. Thermodynamic stabilization of the semiquinone form, in the presence of pyruvate, is interpreted as a mode of regulation of flavocytochrome b2 activity. Taking into account that analogous controls have been observed with two other flavoenzymes belonging to this class of dehydrogenases/one-electron transferases, we suggest that redox potential modulation could be a type of regulation effective for the whole class of enzymes in which a semiquinone is an obligate intermediate.
大肠杆菌丙酮酸氧化酶黄素腺嘌呤二核苷酸结合区的研究。
DOI：
--
发表时间：
1982
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Mather,M;Schopfer,LM;Massey,V;Gennis,RB
通讯作者：
Gennis,RB
琥珀酸脱氢酶中黄素的热力学和电子顺磁共振表征。
DOI：
--
发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Ohnishi,T;King,TE;Salerno,JC;Blum,H;Bowyer,JR;Maida,T
通讯作者：
Maida,T
通过苯甲酸盐结合对 D-氨基酸氧化酶进行热力学控制。
DOI：
--
发表时间：
1985
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
VandenBerghe-Snorek,S;Stankovich,MT
通讯作者：
Stankovich,MT