金属离子在蛋白质中的结合位置。
Where metal ions bind in proteins.
作者信息
Yamashita M M, Wesson L, Eisenman G, Eisenberg D
机构信息
Molecular Biology Institute, University of California, Los Angeles 90024.
出版信息
Proc Natl Acad Sci U S A. 1990 Aug;87(15):5648-52. doi: 10.1073/pnas.87.15.5648.
The environments of metal ions (Li+, Na+, K+, Ag+, Cs+, Mg2+, Ca2+, Mn2+, Cu2+, Zn2+) in proteins and other metal-host molecules have been examined. Regardless of the metal and its precise pattern of ligation to the protein, there is a common qualitative feature to the binding site: the metal is ligated by a shell of hydrophilic atomic groups (containing oxygen, nitrogen, or sulfur atoms) and this hydrophilic shell is embedded within a larger shell of hydrophobic atomic groups (containing carbon atoms). That is, metals bind at centers of high hydrophobicity contrast. This qualitative observation can be described analytically by the hydrophobicity contrast function, C, evaluated from the structure. This function is large and positive for a sphere of hydrophilic atomic groups (characterized by atomic solvation parameters, delta sigma, having values less than 0) at the center of a larger sphere of hydrophobic atomic groups (characterized by delta sigma greater than 0). In the 23 metal-binding molecules we have examined, the maximum values of the contrast function lie near to observed metal binding sites. This suggests that the hydrophobicity contrast function may be useful for locating, characterizing, and designing metal binding sites in proteins.
人们已经对蛋白质和其他金属宿主分子中金属离子（Li⁺、Na⁺、K⁺、Ag⁺、Cs⁺、Mg²⁺、Ca²⁺、Mn²⁺、Cu²⁺、Zn²⁺）的环境进行了研究。无论金属及其与蛋白质精确的连接模式如何，结合位点都有一个共同的定性特征：金属由一层亲水性原子基团（含有氧、氮或硫原子）配位，并且这个亲水性壳层嵌入在一个更大的疏水性原子基团（含有碳原子）壳层中。也就是说，金属在高疏水性对比度的中心结合。这种定性观察可以通过从结构评估的疏水性对比度函数C进行分析描述。对于位于较大疏水性原子基团球体（由δσ大于0表征）中心的亲水性原子基团球体（由原子溶剂化参数δσ表征，其值小于0），该函数大且为正。在我们研究的23个金属结合分子中，对比度函数最大值位于观察到的金属结合位点附近。这表明疏水性对比度函数可能有助于在蛋白质中定位、表征和设计金属结合位点。
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