School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu 225002, P. R. China.
Inorg Chem. 2024 Jul 22;63(29):13602-13612. doi: 10.1021/acs.inorgchem.4c01801. Epub 2024 Jul 7.
Metal nanozymes have offered attractive opportunities for biocatalysis and biomedicine. However, fabricating nanozymes simultaneously possessing highly catalytic selectivity and activity remains a great challenge due to the lack of three-dimensional (3D) architecture of the catalytic pocket in natural enzymes. Here, we integrate rhodium nanocluster (RhNC), reduced graphene oxide (rGO), and protamine (PRTM, a typical arginine-rich peptide) into a composite facilely based on the single peptide. Remarkably, the PRTM-RhNC@rGO composite displays outstanding selectivity, activity, and stability for the catalytic degradation of uric acid. The reaction rate constant of the uric acid oxidation catalyzed by the PRTM-RhNC@rGO composite is about 1.88 × 10 s (4 μg/mL), which is 37.6 times higher than that of reported RhNP ( = 5 × 10 s, 20 μg/mL). Enzyme kinetic studies reveal that the PRTM-RhNC@rGO composite exhibits a similar affinity for uric acid as natural uricase. Furthermore, the uricase-like activity of PRTM-RhNC@rGO nanozymes remains in the presence of sulfur substances and halide ions, displaying incredibly well antipoisoning abilities. The analysis of the structure-function relationship indicates the PRTM-RhNC@rGO composite features the substrate binding site near the catalytic site in a confined space contributed by 2D rGO and PRTM, resulting in the high-performance of the composite nanozyme. Based on the outstanding uricase-like activity and the interaction of PRTM and uric acid, the PRTM-RhNC@rGO composite can retard the urate crystallization significantly. The present work provides new insights into the design of metal nanozymes with suitable binding sites near catalytic sites by mimicking pocket-like structures in natural enzymes based on simple peptides, conducing to broadening the practical application of high-performance nanozymes in biomedical fields.
金属纳米酶为生物催化和生物医学提供了有吸引力的机会。然而，由于天然酶中催化口袋的三维（3D）结构缺乏，制造同时具有高催化选择性和活性的纳米酶仍然是一个巨大的挑战。在这里，我们基于单个肽将铑纳米团簇（RhNC）、还原氧化石墨烯（rGO）和鱼精蛋白（PRTM，一种典型的富含精氨酸的肽）整合到一个复合材料中。值得注意的是，PRTM-RhNC@rGO 复合材料对尿酸的催化降解表现出出色的选择性、活性和稳定性。PRTM-RhNC@rGO 复合材料催化尿酸氧化的反应速率常数约为 1.88×10 s（4 μg/mL），比报道的 RhNP（=5×10 s，20 μg/mL）高 37.6 倍。酶动力学研究表明，PRTM-RhNC@rGO 复合材料对尿酸的亲和力与天然尿酸酶相似。此外，PRTM-RhNC@rGO 纳米酶的尿酸酶样活性在存在硫物质和卤化物离子的情况下仍然存在，表现出令人难以置信的抗中毒能力。结构-功能关系的分析表明，PRTM-RhNC@rGO 复合材料在二维 rGO 和 PRTM 贡献的受限空间中具有靠近催化位点的底物结合位点，从而导致复合材料纳米酶的高性能。基于出色的尿酸酶样活性以及 PRTM 和尿酸之间的相互作用，PRTM-RhNC@rGO 复合材料可以显著延缓尿酸盐结晶。本工作通过基于简单肽模拟天然酶中口袋状结构，为设计具有靠近催化位点的合适结合位点的金属纳米酶提供了新的见解，为高性能纳米酶在生物医学领域的实际应用拓宽了道路。
