Binding of Cu(II) to non-prosthetic sites in ceruloplasmin and bovine serum albumin.
Binding of Cu(II) to non-prosthetic sites in ceruloplasmin and bovine serum albumin.
复制标题
Cu(II) 与铜蓝蛋白和牛血清白蛋白中非修复位点的结合。
DOI：
10.1016/0162-0134(90)80022-p
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发表时间：
1990
影响因子：
3.9
通讯作者：
Frieden,E
中科院分区：
文献类型：
--
作者：
Zgirski,A;Frieden,E
在pH 7.4，30 mM巴比妥缓冲液中，研究了Cu（II）与天然人、猪、牛和绵羊血浆铜蓝蛋白（Cp）和牛血清白蛋白（BSA）的结合。使用Scatchard图分析结果的结合位点的强度和数量。在Cp和BSA中存在额外的铜结合位点的证据表明，铜离子在血清中Cu（II）和其他金属离子的稳态调节中起作用。使用两种流速，4 ml/hr和40 ml/hr，其去除不同亲和力的Cu（II）。在较慢流速下通过的Cp（Cp 4）仅含有假体铜原子。在更快的流速下通过的Cp（Cp 40）含有一个额外的铜原子，其Kga为107 M −1。另一个2-6个Cu（II）离子可以加入到Cp 40中，平均亲和力约为Ka 105 M −1。在Cp中发现的Cu（II）离子提供了两种可区分的类型：（1）辅助铜原子和（2）可以被Chelex-100去除的外源铜原子。对于bSA，一个铜原子与接近1012- 1013 M − 1的Ka值强烈结合，并且在任何流速下都不会被Chelex-100去除。第二个铜原子的Ka= 5.2 × 106 M − 1，可以用Chelex-100以4 ml/hr的速度去除;另外三个铜原子的Ka= 1.6 × 105 M −1，可以用Chelex-100以40 ml/hr的速度去除，但不可透析。
The binding of Cu(II) to native human, porcine, bovine and ovine ceruloplasmin (Cp) and to bovine serum albumin (bSA) has been studied at pH 7.4, 30 mM barbital buffer. The results were analyzed for the strength and the number of binding sites using Scatchard plots. Evidence for additional copper binding sites in Cp and bSA was obtained suggesting a role for copper ion in the homeostatic regulation of Cu(II) and other metal ions in the serum.In the binding studies the Cp was freed of exogenous Cu(II) by passing it over a Chelex-100 column. Two flow rates were used, 4 ml/hr and 40 ml/hr, which removed Cu(II) of different affinities. Cp passed at the slower flow rate (Cp4) only contained the prosthetic copper atoms. Cp passed at the faster flow rate (Cp40) contained one additional copper atom with a Kga∼ 107M−1. Another 2–6 Cu(II) ion could be added to the Cp40with an average affinity of about Ka∼ 105M−1. The Cu(II) ions found in Cp provide two distinguishable classes: (1) the prosthetic copper atoms and (2) the exogenous copper atoms that can be removed by Chelex-100.For bSA one copper atom was bound strongly with a Kavalue approaching 1012–1013M−1and was not removed by Chelex-100 at any flow rate. A second copper atom was found with a Ka= 5.2 × 106M−1and was removed by Chelex-100 at 4 ml/hr. Three additional copper atoms were bound with a Ka= 1.6 × 105M−1; they were readily removed by Chelex-100 at 40 ml/hr but were nondialysable.