University of Padova, Department of Chemical Sciences, via Marzolo, 1 35131 Padova, Italy.
University of Bern, Department of Chemistry and Biochemistry, Freiestrasse 3, CH-3012 Bern, Switzerland.
Molecules. 2019 Aug 1;24(15):2814. doi: 10.3390/molecules24152814.
A series of 2-nm gold nanoparticles passivated with different thiols all featuring at least one triazacyclonanone-Zn(II) complex and different flanking units (a second Zn(II) complex, a triethyleneoxymethyl derivative or a guanidinium of arginine of a peptide) were prepared and studied for their efficiency in the cleavage of the RNA-model substrate 2-hydroxypropyl--nitrophenyl phosphate. The source of catalysis for each of them was elucidated from the kinetic analysis (Michaelis-Menten profiles, pH dependence and kinetic isotope effect). The data indicated that two different mechanisms were operative: One involving two Zn(II) complexes and the other one involving a single Zn(II) complex and a flanking guanidinium cation. The mechanism based on a dinuclear catalytic site appeared more efficient than the one based on the cooperativity between a metal complex and a guanidinium.
一系列由不同硫醇稳定的 2nm 金纳米颗粒均至少含有一个三氮唑并壬酮-Zn(II)配合物和不同侧翼单元（第二个 Zn(II)配合物、三乙氧基甲基衍生物或肽的胍基精氨酸），并对其在切割 RNA 模型底物 2-羟丙基-硝基苯膦酸酯中的效率进行了研究。从动力学分析（米氏曲线、pH 依赖性和动力学同位素效应）中阐明了它们各自的催化来源。数据表明，有两种不同的机制在起作用：一种涉及两个 Zn(II)配合物，另一种涉及单个 Zn(II)配合物和侧翼胍基阳离子。基于双核催化位点的机制似乎比基于金属配合物和胍基之间的协同作用的机制更有效。
