Amphiphilic Amino Acids Regulate Phthalocyanine Or Metal Ions Of Self-assembly Biomimetic Enzyme And Its Catalytic Properties

The natural enzyme is a biomacromolecular catalyst with a three-dimensional active structure,which has extremely high catalytic efficiency and substrate recognition characteristics in the natural catalytic process.These advantages of natural enzyme have greatly promoted scientists' research on biomimetic enzymes.Enzyme mimics have the advantages of low cost,high efficiency and high stability and can be used as a natural enzyme alternative.This alternative plays an important role in organic synthesis,environmental protection,helping to elucidate the catalytic mechanisms of natural enzymes and understanding the evolution of biological enzymes in the origin of life.The design principle of the biomimetic enzyme is mainly to select the key components in the biological enzyme component as host.The hosts of current enzyme mimics are non-protein molecules.These non-protein molecules largely limit the application of enzyme mimics in vivo.At the same time,how to design the catalytic sites,select the host molecules and integrate them into the active three-dimensional structure,and realize the controllable catalytic application is one major challenge.Ordered protein molecular aggregates in nature are mainly assembled with the help of intermolecular interactions including coordination.Inspired by naturally occurring enzyme,we constructed photooxidase mimics and the minimal metallo-nanozyme,further promoting the research of catalytic properties of novel enzyme mimics.The main work is as follows:(1)Here,we developed a photooxidase-mimicking nanovesicles based on small molecule co-assembly.9-Mercaptomethoxycarbonyl-L-histidine(Fmoc-His-OH)and phthalocyanine can be co-assembled into nanovesicles.The biomimetic enzyme has a flexible particle size and film thickness,and an active oxygen species mediated photooxidation capability.Compared to pure phthalocyanine dyes in aqueous solution,phthalocyanine dyes in nanovesicle achieve near-monomolecular dispersion and enhance their fluorescence intensity and ability to produce singlet oxygen.The photocatalytic efficiency and stability in the photosensitive oxidation process are further improved.(2)We proposed a metallo-nanozyme that self-assembles by coordinated amino acids and metal ions.N-(benzyloxycarbonyl)-histidine hydrazide(Z-His-NHNH2)can be flexibly coordinated with zinc to form nanozymes with a tunable particle size and metallo-nanozyme activity.The nano-based supramolecular network based on different metal concentrations mimics the activity of hydrolase,which can be considered as the simplest metallo-nanozyme with good environmental tolerance and can be used as a catalytic carrier for potential artificial prodrugs in future.These work shows that amino acids can regulate phthalocyanine and metal ions to form effective supramolecular catalysts as enzyme mimics.This study solves the problems including the selection of current enzymatic catalytic host,the construction of active structure and the controllable catalysis.The constructed supramolecular photocatalysts can provide ideas for possible evolutionary pathways of simple photocatalytic membrane systems and hydrolases,and can be applied to photosensitive nanoreactors,artificial organelles and potential prodrug delivery in future.