New Selectivity and Turnover in Peptide Hydrolysis by Metal Complexes. A Palladium(II) Aqua Complex Catalyzes Cleavage of Peptides Next to the Histidine Residue
作者:Tatjana N. Parac、Nenad M. Kostić
DOI:10.1021/ja952162e
日期:1996.1.1
the palladium(II)−peptide complex. The cleavage is regioselective. In all the aforementioned dipeptides and in the tripeptide AcGly-His-Gly only the amide bond involving the carboxylic group of histidine is cleaved; the amide bond involving the amino group of histidine is not cleaved. When the carboxylic group of histidine is free, as in AcGly-His, cis-[Pd(en)(H2O)2]2+ does not effect hydrolysis. Lability
这似乎是第一次报告称与组氨酸残基结合的过渡金属络合物会影响该残基旁边的肽的水解裂解。AcHis-Aa 二肽,其中 C 端氨基酸指定为 Aa 为 Gly、Ala、Ser、Thr、Leu、Phe 和 Tyr,在 60 °C 和 1.46 ≤ pD ≤ 2.61 下在 cis-[Pd (en)(H2O)2]2+。通过 1H NMR 光谱可以方便地监测反应,我们报告了动力学。就钯 (II)-肽复合物而言,该反应是单分子的。切割是区域选择性的。在所有上述二肽和三肽 AcGly-His-Gly 中,仅涉及组氨酸羧基的酰胺键断裂;涉及组氨酸氨基的酰胺键未裂解。当组氨酸的羧基游离时,如 AcGly-His,cis-[Pd(en)(H2O)2]2+ 不影响水解。钯 (II) 配合物和酸性溶液的不稳定性使得水解中的适度转变成为可能;催化剂...