Enzyme Mimic Based on a Self-Assembled Chitosan/DNA Hybrid Exhibits Superior Activity and Tolerance
作者：Zhen-Gang Wang, Yunzhe Li, Hui Wang, Kaiwei Wan, Qing Liu, Xinghua Shi, Baoquan Ding
關鍵字：DNA;chitosan;self-assembly;enzyme mimic;
論文來源：期刊
具體來源：Chemistry-A European Journal
發表時間：2019年
Nature has evolved enzymes with exquisite active sites that
catalyze biotransformations with high efficiency. However, the
exploitation of natural enzymes is often hampered by poor stability, and
natural enzyme production and purification are costly. Supramolecular
self‐assembly allows the construction of biomimetic active sites,
although it is challenging to produce such artificial enzymes with
catalytic activity and stability that rival those of natural enzymes. We
report herein a strategy to produce a horseradish peroxidase (HRP)
mimic based on the assembly of chitosan with a G‐quadruplex DNA
(G‐DNA)/hemin complex. A network‐like morphology of the assembled
nanomaterial was observed together with a remarkable enhancement of
peroxidase activity induced by the chitosan and G‐DNA components. The
turnover frequency and catalytic efficiency of the enzyme‐mimicking
material reached or even surpassed those of HRP. Moreover, the catalytic
complex exhibited higher tolerance than HRP to harsh environments, such
as extremely low pH or high temperatures. In accord with the
experimental and simulated results, it is concluded that the spatial
distribution of the G‐DNA and chitosan components and the exposure of
the catalytic center may facilitate the coordination of substrates by
the hemin iron, leading to the superior activity of the material. Our
work provides a simple and affordable avenue to produce highly active
and robust enzyme‐mimicking catalytic nanomaterials.