Laboratoire d'Electrochimie Physique et Analytique, Station 6, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
Metallomics. 2010 Jul;2(7):474-9. doi: 10.1039/c004693k. Epub 2010 May 26.
Copper-β-amyloid 16 (Aβ16) complexes were investigated by electrospray ionization mass spectrometry (ESI-MS). Copper(i) and (ii) complexes were formed on-line in a microchip electrospray emitter by using a sacrificial copper electrode as the anode in positive ionization mode. In the presence of ascorbic acid in the peptide solution, the amount of Cu(i)-Aβ16 generated electrochemically was even higher. A kinetic model is proposed to account for the generation of copper complexes. The structure of Cu(i)-Aβ16 was investigated by tandem mass spectrometry (MS/MS), and the binding site of Cu(i) to Aβ16 was identified at the His13, His14 residues. Cu(ii)-Aβ16 was also investigated by MS/MS and, based on the unusual observations of a-ions, the two binding residues of His13 and His14 of Aβ16 to Cu(ii) were also confirmed. This approach provides direct information on Cu(i)-Aβ16 complexes generated in solution from metallic copper and gives evidence that both His13 and His14 are involved in the coordination of both Cu(i)- and Cu(ii)-Aβ16 complexes.
采用电喷雾电离质谱（ESI-MS）研究了铜-β-淀粉样蛋白 16（Aβ16）复合物。在微芯片电喷雾发射器中，通过使用牺牲铜电极作为阳极在正离子模式下在线形成铜（i）和（ii）复合物。在肽溶液中存在抗坏血酸的情况下，电化学生成的 Cu(i)-Aβ16 的量甚至更高。提出了一个动力学模型来解释铜配合物的生成。通过串联质谱（MS/MS）研究了 Cu(i)-Aβ16 的结构，并确定了 Cu(i)与 Aβ16 的结合位点位于 His13、His14 残基上。还通过 MS/MS 研究了 Cu(ii)-Aβ16，基于对 a-离子的异常观察，也证实了 Aβ16 与 Cu(ii)的 His13 和 His14 两个结合残基。该方法提供了从金属铜在溶液中生成的 Cu(i)-Aβ16 复合物的直接信息，并证明 His13 和 His14 都参与了 Cu(i)-和 Cu(ii)-Aβ16 复合物的配位。
