Zoroddu Maria Antonietta, Kowalik-Jankowska Teresa, Medici Serenella, Peana Massimiliano, Kozlowski Henryk
Department of Chemistry, University of Sassari, Italy.
Dalton Trans. 2008 Nov 28(44):6127-34. doi: 10.1039/b808600a. Epub 2008 Sep 24.
The C-terminal 20 and 30 amino acid sequences of Cap43 protein were chosen as models to study their interactions with Cu(II) ions. The behaviour of the 20 amino acid Ac-TRSRSH6TSEG-TRSRSH16TSEG and 30 amino acid Ac-TRSRSH6TSEG-TRSRSH16TSEG-TRSRSH26TSEG peptides towards Cu(II) ions at different pH values and different ligand-to-metal molar ratios, was examined. Spectroscopic (EPR, UV-Vis) and potentiometric techniques were performed to understand the details of metal binding to the peptides. The study showed that, starting from pH 4.0, each 10 amino acid fragment T1R2S3R4S5H6T7S8E9G10 was able to independently coordinate a single Cu(II) ion. The coordination mode involved the imidazole nitrogen of histidine H6 residue, and three amidic nitrogens from histidine H6, serine S5, and arginine R4 residues, respectively.
选择Cap43蛋白的C末端20个和30个氨基酸序列作为模型，研究它们与铜离子（Cu(II)）的相互作用。研究了20个氨基酸的Ac-TRSRSH6TSEG-TRSRSH16TSEG肽和30个氨基酸的Ac-TRSRSH6TSEG-TRSRSH16TSEG-TRSRSH26TSEG肽在不同pH值和不同配体与金属摩尔比下与铜离子（Cu(II)）的行为。采用光谱（电子顺磁共振、紫外可见光谱）和电位滴定技术来了解金属与肽结合的细节。研究表明，从pH 4.0开始，每个10个氨基酸的片段T1R2S3R4S5H6T7S8E9G10能够独立地配位一个铜离子（Cu(II)）。配位模式分别涉及组氨酸H6残基的咪唑氮，以及来自组氨酸H6、丝氨酸S5和精氨酸R4残基的三个酰胺氮。
