Sheinblatt M
Bioinorg Chem. 1975;5(2):95-106. doi: 10.1016/s0006-3061(00)80054-x.
Reported here are studies on the copper-acetylgylcylglycine system as a function of pH and the molar ratio between the ligand and the paramagnetic ion, applying potentiometric titration, magnetic resonances (esr and nmr) and spectrophotometric techniques. The results indicate that depending on the pH of the solutions there are three distinct regions characterized by their different species and behavior. In region I (pH less than 6.5), the copper is bound to the carboxylate group of the ligand molecule (the "blue" complex). Precipitation of copper occurs in region II (pH-7). In region III (pH greater than 9), in the presence of excess of ligand, the copper redissolves, forming complexes in which the central copper ion binds to the peptide molecule, through the nitrogens of the deprotonated peptide groups, and to hydroxyl ions. The mutual replacement of the peptide groups of chelated AcGlyGly by OH- and the changes in the structures of the complexes are discussed.
本文报道了关于铜-乙酰甘氨酰甘氨酸体系的研究，该研究考察了其作为pH值以及配体与顺磁性离子摩尔比的函数关系，采用了电位滴定、磁共振（电子自旋共振和核磁共振）以及分光光度技术。结果表明，根据溶液的pH值，存在三个不同的区域，其特征在于不同的物种和行为。在区域I（pH小于6.5）中，铜与配体分子的羧酸盐基团结合（“蓝色”络合物）。在区域II（pH = 7）中发生铜的沉淀。在区域III（pH大于9）中，在配体过量的情况下，铜重新溶解，形成络合物，其中中心铜离子通过去质子化肽基团的氮原子与肽分子以及氢氧根离子结合。讨论了氢氧根离子与螯合的乙酰甘氨酰甘氨酸肽基团的相互取代以及络合物结构的变化。
