Construction of Smart Artificial Tellurase Based on the Composite-dissociated Supramolecular Switch
GPx(glutathione peroxidase)is a well-studied selenase in terms of chemical properties and structure,which plays an important role in protecting cells from oxidative stress.In order to better restore the operation mechanism of GPx enzyme under the subtle pH differences in life entity,the preparation of PH-responsive GPx artificial intelligence enzyme has attracted more attention.N-ethylethylamine monotelluride molecule with GPx catalytic center and two secondary amine groups was designed and synthesized.The maximum specific activity value of the molecule was(1.43±0.01)µmol/(min·μmol),the kinetics curve of the enzymatic reaction show that the catalytic mode is an ordered sequence mechanism,and the second-order reaction rate constant could reach the order of 101～102 L/(mol·min).At pH=6,the two secondary amine groups of N-ethylethylamine monotelluride molecule is in the double protonation state,so it could compound with cucurbit[6](CB[6])to form a supramolecular switch.At this time,the catalytic center is embedded in the hydrophobic cavity of CB[6],and the catalytic activity is only(0.18±0.01)μmol/(min·μmol),the artificial enzyme activity is in the off state.At pH=7,the supramolecular switch is partially dissociated,which showed the catalytic activity of(0.67±0.02)μmol/(min·μmol),and the artificial enzyme activity is in the best opening state.Therefore,the supramolecular switch constructed in this paper realized recombination and dissociation in the pH range of living organisms(between 6 and 7),so as to control the off and on of the catalytic activity,providing a new method and idea for constructing Ph-responsive GPx artificial enzymes.
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