Siderophilin metal coordination. Difference ultraviolet spectroscopy of di-, tri-, and tetravalent metal ions with ethylenebis[(o-hydroxyphenyl)glycine].
Siderophilin metal coordination. Difference ultraviolet spectroscopy of di-, tri-, and tetravalent metal ions with ethylenebis[(o-hydroxyphenyl)glycine].
复制标题
亲铁素金属配位。
DOI：
10.1021/bi00527a040
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发表时间：
1981
期刊：
影响因子：
2.9
通讯作者：
Raymond,KN
中科院分区：
文献类型：
--
作者：
Pecoraro,VL;Harris,WR;Carrano,CJ;Raymond,KN
文森特湖韦斯利？佩科拉罗哈里斯，1卡尔J卡拉诺，8和肯尼思N。Raymond* 摘要：为了探索人铁转运蛋白--转铁蛋白中金属离子的配位位点，本文用差示紫外光谱法研究了螯合物类似物亚乙基双[（邻羟基苯基）甘氨酸]（EHPG）与一系列金属离子的络合作用，测定了金属络合物与质子化配体的配位酚的Ac值。除Cu 2+络合物外，在242和290 nm处观察到最大值，在269 nm处观察到最小值。242 nm处的Ac值分为两组。二价金属离子（Zn 2+、Cu 2+和Cd 2+）的络合物具有5000至6600 M-1cm-1的Ac值，而对于三价和四价金属离子（Th 4+、Ga 3+、Fe 3+、Ho 3+、Eu 3+、Er 3+、Tb 3+和VO 2+）的络合物观察到更大的Ac值，为7400-8700 M-1cm-1。已知转铁蛋白结合位点含有酪氨酰残基，但关于结合特定金属离子的酪氨酸基团的精确数目存在相当大的争论。由于通常的做法是假设所有金属离子配位的Ac值都是相同的，因此这里实际观察到的较大范围的Ac值表明，这种假设实际上会导致错误的酪氨酸/金属位点比。的差谱
Vincent L. Pecoraro, Wesley R. Harris, 1 Carl J. Carrano, 8 and Kenneth N. Raymond* abstract: So that the metal ion coordination site in the human iron transport protein, transferrin, could be probed, the complexation of a series of metal ions by the chelate analogue ethylenebis [(o-hydroxyphenyl) glycine](EHPG) has been studiedby difference UV spectroscopy, in which Ac values per coordinated phenol have been determined for the metal complex vs. the protonated form of the ligand. With the exception of the Cu2+ complex, maxima are observed at 242 and 290 nm with a minimum at 269 nm. The Ac values at 242 nm fall intotwo groups. Complexes of divalent metal ions (Zn2+, Cu2+, and Cd2+) have Ac values ranging from 5000 to 6600 M" 1 cm" 1 whereas larger Ac values are observed for complexes of tri-and tetravalent metal ions (Th4+, Ga3+, Fe3+, Ho3+, Eu3+, Er3+, Tb3+, and V02+), 7400-8700 M" 1 cm" 1. It is known that the transferrin binding sites contain tyrosyl residues, but there has been considerable debate concerning the precise number of tyrosine groups which bind to specific metal ions. Since it has been the common practice to assume that the Ac values for coordinationby all metal ions are identical, the larger range of Ac values actually observed here shows that such an assumption can actually lead to an erroneous tyrosine/metal site ratio. The difference spectra of