Jul 9 2021
工业酶催化的两个主要挑战是在工业催化中恶劣条件下酶催化的化学反应类型的数量有限和酶的不稳定性。
迫切需要将酶催化扩大到较大的底物范围和更大的化学反应，并迫切需要调整周围酶分子的微环境以实现高酶性能。
最近，由Tsinghua大学的Jun GE教授领导的一支研究团队，使用从Novo的方法合成混合酶催化剂，审查了他们的努力，该方法可以解决这两个挑战，并讨论了结构功能关系，以揭示设计混合动力的原理酶催化剂。结果发表在中国催化杂志.
In 2012, they first reported a coprecipitation method to prepare enzyme-inorganic-crystal composites. The coprecipitation method is general for preparing hybrid enzyme catalysts with various inorganic crystals, including MOFs. In 2014, they first proposed a coprecipitation strategy for directly synthesizing protein-embedded MOFs. The coprecipitation strategy for synthesizing enzyme-MOF composites is widely used in different types of MOFs, enzymes, proteins, DNA, siRNA, antibodies, and even cells. The mechanisms of enhancement of activity and stability of enzymes in the confined environment of MOFs were discussed. In addition to this, they constructed multienzyme-MOF composites to enhance the cascade reaction in a confined scaffold and developed a coarse-grained, particle-based model to understand the origin of the activity enhancement.
The apparent activity of enzymes in MOFs with a limited pore size is usually compromised when the enzyme substrate has a relatively high molecular weight. By introducing defects within the MOF matrix to generate larger pores, diffusional restrictions can be alleviated. Therefore, they developed methods for introducing defects into MOFs during coprecipitation. Tuning the concentration of precursors of MOFs, defected and even amorphous MOFs can be synthesized. These defects created mesopores in the composites, facilitated access of the substrates to the encapsulated enzymes and improved the apparent enzyme activity. The mechanism of defect generation was thoroughly studied and understood.
Moreover, instead of enzyme encapsulation, small inorganic crystals can grow in situ in a confined environment on the surface of an enzyme to combine enzymatic catalysis and chemocatalysis. They demonstrated how to construct an enzyme-metal hybrid catalyst to efficiently combine enzyme catalysis and metal cluster catalysis. Single lipase-polymer conjugates as confined nanoreactors were utilized for the in situ generation of Pd nanoparticles/clusters to accomplish chemoenzymatic dynamic kinetic resolution (DKR) of amines. The distinct size-dependent activity of Pd nanoparticles was observed. Experiments and simulations suggested that the engineering of the oxidation state of Pd plays an important role in the activity of Pd in the hybrid catalyst. This strategy for constructing enzyme-metal hybrid catalysts with excellent compatibility between enzymatic and metal-catalytic activities leads to many potential applications in chemical industry.
这项工作得到了北京自然科学基金会（JQ18006），中国国家主要研发计划（2016yfa020亚博老虎机网登录4300）和中国国家自然科学基金会（21622603，21878174，21911540467）的支持。
来源：https://english.cas.cn/