在酶催化中,氧化还原位点和路易斯酸是金属辅助氨基酸的两个主要作用。然而,报道的酶模拟只关注氧化还原活性金属作为氧化还原位点,而氧化还原惰性金属如路易斯酸,据我们所知,没有被研究,呈现酶模拟构建的瓶颈。基于此,报道了一系列以钒为氧化还原位点和碱土金属离子(M2)为路易斯酸的高效MxV2O5·nH2O过氧化物酶模拟物。实验结果和理论计算表明,MxV2O5·nH2O的过氧化物酶模拟活性随M2的Lewis酸度(离子势)呈周期性变化,揭示了氧化还原惰性M2通过非共价极化调节V-O电子转移从而促进H2O2吸附物解离的机理。氧化还原位点和路易斯酸的仿生协同作用有望为酶模拟物的设计提供启发。
In enzymatic catalysis, the redox site and Lewis acid are the two main roles played by metal to assist amino acids. However, the reported enzyme mimics only focus on the redox-active metal as redox site, while the redox-inert metal as Lewis acid has, to the best of our knowledge, not been studied, presenting a bottleneck of enzyme mimics construction. Based on this, a series of highly efficient MxV2O5·nH2O peroxidase mimics with vanadium as redox site and alkaline-earth metal ion (M2+) as Lewis acid are reported. Experimental results and theoretical calculations indicate the peroxidase-mimicking activity of MxV2O5·nH2O show a periodic change with the Lewis acidity (ion potential) of M2+, revealing the mechanism of redox-inert M2+ regulating electron transfer of V-O through non-covalent polarization and thus promoting H2O2 adsorbate dissociation. The biomimetic synergetic effect of redox site and Lewis acid is expected to provide an inspiration for design of enzyme mimics.