Characterizing the effects of the protein environment on the reduction potentials of metalloproteins.
Characterizing the effects of the protein environment on the reduction potentials of metalloproteins.
复制标题
表征蛋白质环境对金属蛋白质还原电位的影响。
DOI：
10.1007/s00775-012-0955-3
复制
发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Ichiye,Toshiko
中科院分区：
文献类型：
--
作者：
PerrinJr,BradleyScott;Ichiye,Toshiko
电子转移蛋白的还原电位主要由蛋白质内氧化还原位点的埋藏程度和氧化还原位点周围多肽的永久极化程度决定。虽然蛋白质结构的连续静电计算可以预测这些因素的净效应，量化每个单独的贡献是一项艰巨的任务。在这里，氧化还原位点的掩埋的特征在于介电半径Rp（蛋白质的Born型半径），多肽的极化的特征在于驻极体电势EDP（金属原子处的平均静电势），并且整个蛋白质的驻极体-介电球（EDS）模型然后根据Rp和EDP来定义。EDS模型表明，对于具有电荷Q的氧化还原位点的蛋白质，介电响应自由能是Q 2的函数，而驻极体能量是Q的函数。此外，Rp和Rp是蛋白质折叠的特征，并且是经历不同氧化还原对的氧化还原位点的最可能的氧化还原对的预测。
The reduction potentials of electron transfer proteins are critically determined by the degree of burial of the redox site within the protein and the degree of permanent polarization of the polypeptide around the redox site. Although continuum electrostatics calculations of protein structures can predict the net effect of these factors, quantifying each individual contribution is a difficult task. Here, the burial of the redox site is characterized by a dielectric radiusRp(a Born-type radius for the protein), the polarization of the polypeptide is characterized by an electret potentialϕp(the average electrostatic potential at the metal atoms), and an electret-dielectric spheres (EDS) model of the entire protein is then defined in terms ofRpandϕp. The EDS model shows that for a protein with a redox site of chargeQ, the dielectric response free energy is a function ofQ2, while the electret energy is a function ofQ. In addition,Rpandϕpare shown to be characteristics of the fold of a protein and are predictive of the most likely redox couple for redox sites that undergo different redox couples.