Yeast cytochrome c with phenylalanine or tyrosine at position 87 transfers electrons to (zinc cytochrome c peroxidase)+ at a rate ten thousand times that of the serine-87 or glycine-87 variants.
Yeast cytochrome c with phenylalanine or tyrosine at position 87 transfers electrons to (zinc cytochrome c peroxidase)+ at a rate ten thousand times that of the serine-87 or glycine-87 variants.
复制标题
87 位具有苯丙氨酸或酪氨酸的酵母细胞色素 c 将电子转移至（锌细胞色素 c 过氧化物酶），其速度是丝氨酸 87 或甘氨酸 87 变体的一万倍。
DOI：
10.1073/pnas.84.5.1249
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发表时间：
1987
影响因子：
11.1
通讯作者：
Hoffman,BM
中科院分区：
文献类型：
--
作者：
Liang,N;Pielak,GJ;Mauk,AG;Smith,M;Hoffman,BM
在已知的影响两种金属蛋白之间电子转移速率的许多因素中，评估多肽基质在供体和受体位点之间的作用尤其困难。为了确定在系统发育上保守的酵母iso1 -细胞色素c的ph -87是否有助于介导细胞色素c和细胞色素c过氧化物酶之间的电子转移，我们构建了细胞色素c在该位置发生改变的突变体，现在研究了它们与锌取代的细胞色素c过氧化物酶配合物内的远程电子转移动力学。我们发现，当苯丙氨酸或酪氨酸存在于87位时，电子从还原的细胞色素c转移到锌细胞色素c过氧化物酶阳离子自由基的速率比存在丝氨酸或甘氨酸时高4个数量级。
Of the many factors known to influence the rate of electron transfer between two metalloproteins, it is particularly difficult to assess the role of the polypeptide matrix intervening between the donor and acceptor sites. To determine whether the phylogenetically conserved Phe-87 of yeast iso-1-cytochrome c helps to mediate electron transfer between cytochrome c and cytochrome c peroxidase, we have constructed mutants of cytochrome c that are altered at this position and now have studied the kinetics of long-range electron transfer within their complexes with zinc-substituted cytochrome c peroxidase. We find that the rate of electron transfer from reduced cytochrome c to the zinc cytochrome c peroxidase pi-cation radical is four orders of magnitude greater when phenylalanine or tyrosine is present at position 87 than when serine or glycine is present.