P450BM-3: reduction by NADPH and sodium dithionite.
P450BM-3: reduction by NADPH and sodium dithionite.
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P450BM-3：被NADPH和连二亚硫酸钠还原。
DOI：
10.1016/0003-9861(92)90738-i
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发表时间：
1992
影响因子：
3.9
通讯作者：
Boddupalli,SS
中科院分区：
文献类型：
--
作者：
Peterson,JA;Boddupalli,SS
微粒体P450催化多种疏水化合物的单氧合作用，包括药物、类固醇、致癌物质和脂肪酸。在电子从NADPH转移到P450的过程中，微体P450与其电子转移伙伴NADPH-P450还原酶的相互作用可能在调节这一酶系统中起重要作用。高度纯化的巨大芽孢杆菌P450BM-3是催化自给自足的，在大约12万Da的单一多肽链上同时含有还原酶和P450结构域。P450BM-3的两个结构域似乎在功能上相似，在序列上与微粒体P450系统组件同源。在纯化的P450BM-3中，FAD、FMN和血红素残基以等摩尔量存在，因此，在还原滴定过程中，该蛋白质可能会接受每摩尔酶5个电子当量。在一氧化碳气氛下用二亚硫酸钠滴定P450BM-3，并添加了预期的五个电子当量。中间光谱表明，血红素铁首先被还原，其次是黄素残留物。当反应在一氧化碳气氛下进行时，用生理还原剂NADPH滴定蛋白质也需要大约5个电子当量。在Ar气氛和无一氧化碳的情况下，黄素基团中的一个基团在还原血红素基团之前被还原。P450BM-3与NADPH的滴定行为令人惊讶，因为没有观察到黄素半喹酮中间体的光谱特征变化。用NADPH滴定的结果只能在以下情况下才能解释：(A)P450BM-3分子之间存在“快速”的分子间电子转移，(B)单电子还原形式的还原酶对P450的还原没有动力学障碍，以及(C)在这种复杂的多结构域酶中不积累“空气稳定的半喹酮”形式的还原酶。
Microsomal P450s catalyze the monooxygenation of a large variety of hydrophobia compounds, including drugs, steroids, carcinogens, and fatty acids. The interaction of microsomal P450s with their electron transfer partner, NADPH-P450 reductase, during the transfer of electrons from NADPH to P450, for oxygen activation, may be important in regulating this enzyme system. Highly purifiedBacillus megateriumP450BM-3is catalytically self-sufficient and contains both the reductase and P450 domains on a single polypeptide chain of approximately 120,000 Da. The two domains of P450BM-3appear to be analogous in their function and homologous in their sequence to the microsomal P450 system components. FAD, FMN, and heme residues are present in equimolar amounts in purified P450BM-3and, therefore, this protein could potentially accept five electron equivalents per mole of enzyme during a reductive titration. The titration of P450BM-3with sodium dithionite under a carbon monoxide atmosphere was complete with the addition of the expected five electron equivalents. The intermediate spectra indicate that the heme iron is reduced first, followed by the flavin residues. Titration of the protein with the physiological reductant, NADPH, also required approximately five electron equivalents when the reaction was performed under an atmosphere of carbon monoxide. Under an atmosphere of argon and in the absence of carbon monoxide, one of the flavin groups was reduced prior to the reduction of the heme group. The titration behavior of P450BM-3with NADPH was surprising because no spectral changes characteristic of flavin semiquinone intermediates were observed. The results of the titration with NADPH can only be explained if (a) there was “rapid” intermolecular electron transfer between P450BM-3molecules, (b) there is no kinetic barrier to the reduction of P450 by the one-electron-reduced form of the reductase, and (c) the “air-stable semiquinone” form of the reductase does not accumulate in this complex multidomain enzyme.
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DOI：
10.1016/s0021-9258(18)62872-8
发表时间：
1970-09
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
H. Strobel;A. Y. Lu;J. Heidema;M. J. Coon
通讯作者：
H. Strobel;A. Y. Lu;J. Heidema;M. J. Coon
影响因子：
2.9
作者：
IYANAGI, T;MASON, HS
通讯作者：
MASON, HS
纯化的大鼠肝细胞色素 P-450 的还原动力学。
影响因子：
2.9
作者：
Tamburini,PP;Gibson,GG;Backes,WL;Sligar,SG;Schenkman,JB
通讯作者：
Schenkman,JB
NADPH浓度对细胞色素P-450 LM2还原的影响。
DOI：
10.1016/s0021-9258(19)57385-9
发表时间：
1988
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
W. Backes;C. E. Reker
通讯作者：
C. E. Reker
氯贝特诱导的大鼠肝 P450 IVA1 和 IVA3 催化脂肪酸的 omega-和 (omega-1)-羟基化以及前列腺素 E1 和 F2 α 的 omega-羟基化。
影响因子：
6.5
作者：
T. Aoyama;J. Hardwick;S. Imaoka;Y. Funae;Gelboin Hv;F. J. Gonzalez
通讯作者：
F. J. Gonzalez