Departament de Química Analítica, Universitat de Barcelona, Spain.
Anal Biochem. 2010 Nov 1;406(1):61-9. doi: 10.1016/j.ab.2010.06.034. Epub 2010 Jul 1.
Multivariate curve resolution with alternating least squares (MCR-ALS) was applied to voltammetric data obtained in the analysis of the competitive binding of glutathione (GSH) and phytochelatins [(gammaGlu-Cys)(n)-Gly, PC(n), n=2-5] by Cd(2+). The displacements between ligands and chain length influence on the competitive binding of PC(n) toward Cd(2+) were investigated. The analysis of the resulting pure voltammograms and concentration profiles of the resolved components suggests that ligands containing more thiol groups are able to displace the shortest chain ligands from their metal complexes, whereas the opposite does not happen. However, when the length of the chain surpasses that of PC(3), the binding capacity of the molecule still increases (i.e., it can bind more metal ions), but the position and shape of the voltammetric signals practically rest unchanged. This suggests that at this level, the stability of metal binding could depend more on the nature of the binding sites separately than on the quantity of the sites (i.e., the chain length).
多变量曲线分辨与交替最小二乘法 (MCR-ALS) 被应用于通过 Cd(2+) 分析谷胱甘肽 (GSH) 和植物螯合肽 [(γGlu-Cys)(n)-Gly，PC(n)，n=2-5] 的竞争结合的伏安数据。研究了配体的位移和链长对 PC(n) 与 Cd(2+) 的竞争结合的影响。对得到的纯伏安图和分辨成分的浓度分布进行分析表明，含有更多巯基的配体能够从它们的金属配合物中置换最短链的配体，而反之则不行。然而，当链长超过 PC(3)时，分子的结合能力仍然增加（即，它可以结合更多的金属离子），但伏安信号的位置和形状几乎不变。这表明在这个水平上，金属结合的稳定性可能更多地取决于单独的结合位点的性质，而不是数量（即链长）。
