A microsomal cytochrome reductase specific for diphosphopyridine nucleotide.
A microsomal cytochrome reductase specific for diphosphopyridine nucleotide.
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一种对二磷酸吡啶核苷酸具有特异性的微粒体细胞色素还原酶。
DOI：
10.1016/s0021-9258(18)65247-0
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发表时间：
1956
期刊：
影响因子：
--
通讯作者：
S. Velick
中科院分区：
文献类型：
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作者：
P. Strittmatter;S. Velick
方法采用Beckman DU型分光光度计，对汞弧的几个发射带进行校准，用于大多数分析。需要时，厌氧技术与先前描述的技术相似（7）。在微粒体细胞色素的情况下，还原过程中423 rnp处的E1作为从定量吸收光谱和滴定实验获得的值的平均值（6，7）。在含有微粒体细胞色素和细胞色素c的测定系统中，在550 mp下进行细胞色素c的还原。微粒体细胞色素对该波长处光谱变化的贡献可以忽略不计，原因如下：（a）细胞色素c总是以5- 20倍的摩尔过量存在，（B）在550 mp处细胞色素c的摩尔吸收变化是微粒体细胞色素的3倍，（c）在用微粒体细胞色素还原细胞色素c的过程中，（c）* 这项工作得到了美国癌症协会根据国家研究理事会增长委员会的建议提供的赠款的帮助。1使用了以下缩写：DPNH，还原的二磷酸吡啶核苷酸; TPNH，还原的三磷酸吡啶核苷酸; Verdine，乙二胺四乙酸的商品名; Tris缓冲液，由三（羟甲基）氨基甲烷制备的缓冲液; PCMBS，对氯汞苯磺酸盐。
MethodsThe Beckman model DU spectrophotometer, calibrated against several emission bands of a mercury arc, was used for most of the assays. Anaerobic techniques, when required, were similar to those previously described (7). In the case of the microsomal cytochrome, the E,, at 423 rnp during reduction was taken as the average of values obtained from quantitative absorption spectra and titration experiments (6, 7). With assay systems containing both the microsomal cytochrome and cytochrome c, the reduction of the cytochrome c was followed at 550 mp. The contribution of the microsomal cytochrome to spectral changes at this wave-length was negligible for the following reasons:(a) cytochrome c was always present in a 5-to 20-fold molar excess,(b) the molar absorption change at 550 mp is three times greater for cytochrome c than for the microsomal cytochrome, and (cj, during cytochrome c reduction with the microsomal cytochrome as* This work was aided by a grant from the American Cancer Society on recommendation of the Committee on Growth of the National Research Council. 1 The following abbreviations are used: DPNH, reduced diphosphopyridine nucleotide; TPNH, reduced triphosphopyridine nucleotide; Versene, trade name for ethylenediaminetetraacetic acid; Tris buffer, a buffer prepared from tris (hydroxymethyl) aminomethane; PCMBS, p-chloromercuribenzene sulfonate.