MECHANISM OF THE SUPEROXIDE-PRODUCING OXIDASE OF NEUTROPHILS - O-2 IS NECESSARY FOR THE FAST REDUCTION OF CYTOCHROME B-245 BY NADPH
MECHANISM OF THE SUPEROXIDE-PRODUCING OXIDASE OF NEUTROPHILS - O-2 IS NECESSARY FOR THE FAST REDUCTION OF CYTOCHROME B-245 BY NADPH
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DOI：
10.1042/bj2260881
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发表时间：
1985-01-01
影响因子：
4.1
通讯作者：
JONES, OTG
中科院分区：
文献类型：
--
作者：
CROSS, AR;PARKINSON, JF;JONES, OTG
从佛波醇刺激的猪中性粒细胞的可溶性氧化酶含有FAD和细胞色素B-245。典型的制备产生13.03mol的超氧化物（O2-.）. cntdot. s-1.cntdot. mol细胞色素B-1（348 nmol. min-1. mg蛋白质-1）。在有氧稳态下，细胞色素B减少8.9%。稳态细胞色素B还原是从未受刺激的细胞提取物缺席; Km值为NADPH，为O2-。生产和细胞色素B还原是相似的。计算的细胞色素B还原的好氧速率等于测量的O2-速率。在各种制剂中和在一系列抑制剂的存在下生产。在厌氧条件下的速度是缓慢的：O2显然是需要快速的电子流到氧化酶复合物。细胞色素B在动力学上可作为O2-.-生成复合体。
A soluble oxidase from phorbol-stimulated pig neutrophils contained FAD and cytochrome b-245. A typical preparation produced 13.03 mol of superoxide (O2-.) .cntdot. s-1 .cntdot. mol of cytochrome b-1 (348 nmol .cntdot. min-1 .cntdot. mg of protein-1). In the aerobic steady state, cytochrome b was 8.9% reduced. Steady-state cytochrome b reduction was absent from extracts of unstimulated cells; Km values for NADPH, for O2-. production and cytochrome b reduction were similar. The calculated aerobic rate of cytochrome b reduction was equal to the measured rate of O2-. production in a variety of preparations and in the presence of a range of inhibitors. Under anaerobic conditions the rate was slow: O2 is apparently required for rapid electron flow into the oxidase complex. Cytochrome b is shown to be kinetically competent to act as part of the O2-.-generating complex.