Wertz Ashlee E, Rosenkampff Ilmari, Ibouanga Philippe, Huber Matthias, Hess Corinna R, Rüdiger Olaf, Shafaat Hannah S
Department of Chemistry and Biochemistry, The Ohio State University, 100 W 18th Ave, Columbus, OH, 43210, USA.
Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.
J Biol Inorg Chem. 2025 Feb;30(1):13-23. doi: 10.1007/s00775-025-02095-z. Epub 2025 Feb 1.
Native metalloenzymes are unparalleled in their ability to perform efficient small molecule activation reactions, converting simple substrates into complex products. Most of these natural systems possess multiple metallocofactors to facilitate electron transfer or cascade catalysis. While the field of artificial metalloenzymes is growing at a rapid rate, examples of artificial enzymes that leverage two distinct cofactors remain scarce. In this work, we describe a new class of artificial enzymes containing two different metallocofactors, incorporated through bioorthogonal strategies. Nickel-substituted rubredoxin (Ni), which is a structural and functional mimic of [NiFe] hydrogenases, is used as a scaffold. Incorporation of a synthetic bimetallic inorganic complex based on a macrocyclic biquinazoline ligand (M) was accomplished using a novel chelating thioether linker. Neither the structure of the Ni active site nor the M were altered upon attachment, and each site retained independent redox activity. Electrocatalysis was observed from each site, with the switchability of the system demonstrated through the use of catalytically inert metal centers. This M-Ni platform offers a new avenue to create multicofactor artificial metalloenzymes in a robust system that can be easily tuned both through modifications to the protein scaffold and the synthetic moiety, with applications for redox catalysis and tandem reactivity.
天然金属酶在进行高效小分子活化反应、将简单底物转化为复杂产物的能力方面无与伦比。这些天然体系中的大多数都拥有多种金属辅因子，以促进电子转移或级联催化。虽然人工金属酶领域正在迅速发展，但利用两种不同辅因子的人工酶实例仍然很少。在这项工作中，我们描述了一类新的人工酶，它含有两种不同的金属辅因子，通过生物正交策略引入。镍取代的铁氧化还原蛋白（Ni）是[NiFe]氢化酶的结构和功能模拟物，用作支架。使用新型螯合硫醚连接体实现了基于大环双喹唑啉配体（M）的合成双金属无机配合物的引入。连接后，Ni活性位点的结构和M均未改变，每个位点都保留了独立的氧化还原活性。从每个位点都观察到了电催化作用，通过使用催化惰性金属中心证明了该体系的可切换性。这个M-Ni平台为在一个强大的体系中创建多辅因子人工金属酶提供了一条新途径，该体系可以通过对蛋白质支架和合成部分的修饰轻松调节，可用于氧化还原催化和串联反应。
