Institute of Condensed Matter and Nanosciences, Bio- and Soft Matter , Université Catholique de Louvain , 1348 Louvain-la-Neuve , Belgium.
J Am Chem Soc. 2018 Apr 18;140(15):5179-5184. doi: 10.1021/jacs.8b00872. Epub 2018 Apr 3.
Confinement and cooperativity are important design principles used by Nature to optimize catalytic activity in enzymes. In these biological systems, the precise sequence of the protein encodes for specific chain folding to preorganize critical amino acid side chains within defined binding pockets, allowing synergistic catalytic activation pathways to be expressed and triggered. Here we show that short synthetic precision oligomers with the optimal sequence of catalytic units, spatially arranged by dense surface grafting to form confined cooperative "pockets", display an up to 5-fold activity improvement compared to a "mismatched" sequence or free oligomers using the (pyta)Cu/TEMPO/NMI-catalyzed aerobic selective oxidation of alcohols as a model reaction. We thus demonstrate that, in analogy with enzymes, sequence definition combined with surface grafting induce the optimized distribution, both radially (interchain) and axially (intrachain), of a catalytic triad, and that the impressive improvement of catalytic efficiency results predominantly from "matched" interchain interactions in the surface-confined system, thereby outperforming the homogeneous system. The concept presented here hence uncovers a new paradigm in the design of multifunctional molecular assemblies to control functions at a level approaching biological precision.
限制和协同作用是自然界用来优化酶催化活性的重要设计原则。在这些生物系统中,蛋白质的精确序列编码特定的链折叠,以预先组织关键氨基酸侧链在定义的结合口袋内,从而表达和触发协同催化激活途径。在这里,我们展示了具有最佳催化单元序列的短合成精确寡聚物,通过密集的表面接枝空间排列形成受限协同“口袋”,与“不匹配”序列或使用(pyta)Cu/TEMPO/NMI 催化的有氧选择性氧化醇的自由寡聚物相比,活性提高了 5 倍作为模型反应。因此,我们证明了,与酶类似,序列定义与表面接枝相结合,诱导催化三联体的优化分布,无论是径向(链间)还是轴向(链内),并且令人印象深刻的催化效率的提高主要来自于表面受限系统中“匹配”的链间相互作用,从而优于均相体系。因此,这里提出的概念揭示了一种新的多功能分子组装设计范式,可以控制接近生物学精度的功能。