Interflavin oxidation-reduction reactions between pig kidney general acyl-CoA dehydrogenase and electron-transferring flavoprotein.
Interflavin oxidation-reduction reactions between pig kidney general acyl-CoA dehydrogenase and electron-transferring flavoprotein.
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猪肾酰基辅酶A脱氢酶与电子传递黄素蛋白之间的间黄素氧化还原反应。
DOI：
10.1021/bi00345a015
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发表时间：
1985
期刊：
影响因子：
2.9
通讯作者：
Thorpe,C
中科院分区：
文献类型：
--
作者：
Gorelick,RJ;Schopfer,LM;Ballou,DP;Massey,V;Thorpe,C
用静态吸光度、停流吸光度和荧光法研究了猪肾通用酰辅酶A脱氢酶(GAD)与其生理受体电子转移黄素蛋白(ETF)之间的黄素电子传递机制。在温度为3℃，pH为7.6的条件下，ETF对化学计量比为辛酰辅酶A还原的脱氢酶的再氧化是多相的，由两个快速相组成(Rly)。20ms和50ms)，一个较慢的阶段，大约1个S完成了一半，最终的反应是20个S的半场。只有最快的两个阶段才是显著的周转。通过考察GAD2e-P+ETFle、GADle-P+ETF0X和GADle-P+ETFle(其中P代表产物辛烯基-辅酶A，下标表示黄素的氧化还原状态)这一看似合理的各个步骤的速率，剖析了这一复杂的反应过程。在所有情况下，快速反应和静态荧光测量都表明，最终的平衡混合物中含有相当数量的氧化ETF。通过测定ETFle+GAD0X-P、ETFle+GADle-P和ETF2e+GAD0X-P的反向反应证实了这一点。这些数据支持GAD2e-P与ETF0X反应的总体方案：第一和第二阶段对应于GAD2e-P在两个连续的单电子步骤中的再氧化，需要两个ETF0X分子。这导致在370 nm处的吸光度迅速上升，此时产物络合脱氢酶和ETF的红色阴离子自由基都有很强的吸收。370 nm吸光度的较慢下降反映了ETFle1被产物络合酶的单电子和两电子还原形式进一步还原。根据所提出的方案，在辛烯基-CoA存在下，ETF半醌的歧化反应是由脱氢酶催化的，该歧化反应有助于在较慢的相中保持最终的平衡。在没有结合产物的情况下，GAD2e对ETF0X的还原遵循不同的过程，完成的速度要慢得多。初始的单电子转移生成蓝色脱氢酶半喹酮(Tx×2=600ms，在3℃时)，并伴随着ETF红色自由基的形成。ETFle的进一步还原进行得非常缓慢(tl/2=60 S)，伴随着脱氢酶自由基的再氧化。这些数据证实了在底物还原酶通过电子转移黄素蛋白进行再氧化的过程中，酰基辅酶A产物在调节脱氢酶的热力学和动力学行为中所起的重要作用。
The mechanism of interflavin electron transfer between pig kidney general acyl-CoA dehydrogenase (GAD) and its physiological acceptor, electron-transferring flavoprotein (ETF), has been studied by static and stopped-flow absorbance and fluorescence measurements. At 3 C, pH 7.6, reoxidation of the dehydrogenase (stoichiometrically reduced by octanoyl-CoA) by ETF is multiphasic, consisting of two rapid phases (rly. 2 of about 20 and 50 ms), a slower phase half-complete in about 1 s, and a final reaction with a half-time of 20 s. Only the two most rapid phases are significant inturnover. This complicated reaction course was dissected by examining the rates of plausible individual steps, eg, GAD2e-P+ ETFle, GADle-P+ ETF0X, and GADle-P+ ETFle (where P representsthe product, octenoyl-CoA, and the subscripts indicate the redoxstate of the flavin). Rapid reaction and static fluorescence measurements, in all cases, showed that the final equilibrium mixture included appreciable levels of oxidized ETF. This was confirmed by measuring the reverse reactions, eg, ETFle+ GAD0X-P, ETFle+ GADle-P, and ETF2e+ GAD0X-P. These data support the following overall scheme for the reaction of GAD2e-P with ETF0X: The first and second phases correspond to reoxidation of GAD2e-P in two successive one-electron steps requiring two molecules of ETF0X. This results in a rapid rise in absorbance at 370 nm where the red anionic radicals of both product-complexed dehydrogenase and ETF absorb strongly. The slower decline in 370-nm absorbance reflects further reduction of ETFleby one-and two-electron-reduced forms of the product-complexed enzyme. In accord with the proposed scheme, the disproportionation of ETF semiquinone is catalyzed by the de-hydrogenase in the presence of octenoyl-CoA, and thisdisproportionation reaction contributes to the at-tainment of the final equilibrium in the slower phases. In the absence of bound product, the reductionofETF0X by GAD2e follows a different course, proceeding much more slowly to completion. Initial one-electron transfer generates the blue dehydrogenase semiquinone (tx¡ 2= 600 ms at 3 C) with concomitant formation of ETF red radical. Further reduction of ETFle proceeds very slowly (tl/2= 60 s), with concomitant reoxidation of the dehydrogenase radical. These data identify the important role played by acyl-CoA product in modulation of the thermodynamic and kinetic behavior of the dehydrogenase during the reoxidationof substrate-reduced enzyme by electron-transferring flavoprotein.
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高效液相色谱法分离和测定正常大鼠组织中的视黄基脂肪酰酯。
影响因子：
4.1
作者：
P. Bhat;A. Lacroix
通讯作者：
A. Lacroix
维生素 A 与大鼠生殖
DOI：
--
发表时间：
1964
期刊：
Proceedings of the Royal Society of London. Series B. Biological Sciences
影响因子：
--
作者：
J. Thompson;J. Howell;G. Pitt
通讯作者：
G. Pitt
DOI：
10.1016/s0021-9258(17)38759-8
发表时间：
1985-11
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
R. Blomhoff;M. Rasmussen;A. Nilsson;K. Norum;T. Berg;W. Blaner;M. Kato;J. Mertz;D. Goodman;U. Eriksson
通讯作者：
R. Blomhoff;M. Rasmussen;A. Nilsson;K. Norum;T. Berg;W. Blaner;M. Kato;J. Mertz;D. Goodman;U. Eriksson
类维生素A营养状态对各种大鼠组织中细胞视黄醇和细胞视黄酸结合蛋白浓度的影响。
DOI：
--
发表时间：
1985
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Kato,M;Blaner,WS;Mertz,JR;Das,K;Kato,K;Goodman,DS
通讯作者：
Goodman,DS
细胞视黄醇结合蛋白和细胞视黄酸结合蛋白在大鼠睾丸和附睾中的定位。
影响因子：
--
作者：
Porter,SB;Ong,DE;Chytil,F;Orgebin-Crist,MC
通讯作者：
Orgebin-Crist,MC