Design,Synthesis And Characterization Of Artificial Ion Channel Based On New Polypeptide Units

Cell is the basic unit that constitutes the structure and function of all life activities.The cell membrane is a lipid bilayer membrane formed by self-assembly of phospholipid molecules,which plays an important role in maintaining the physiological environment and physiological signal transmission in the cells.The maintenance of normal physiological activities by cells requires constant exchange of materials from the outside,in which membrane proteins with transmembrane transport function play a key role.Natural membrane proteins have a high transport efficiency and selectivity during the transmembrane transport.However,these transmembrane proteins have complex structures,and are easy to lose activity once left the biofilm,the membrane protein structure analysis and the mechanism investigation of material transmembrane transport is not deep.In order to study the mechanism of transmembrane transport,chemical workers have designed and synthesized a variety of artificial channel systems on the basis of natural prototype in recent years.In spite of the research on artificial channel has made a great progress,there is a demand for the design of artificial transmembrane channels with high selectivity and transportation efficiency.The work of this paper mainly includes the following two parts:In the first part,we designed and synthesized a class of helical tubular molecules based on pillar[5]arene-peptides as the skeleton.Through the proton transmembrane transport fluorescence experiments,we proved that these molecules have a good ability to incorporate into lipid membranes.And with the increase of the channel length,these artificial transmembrane channels showed increased incorporation ability.According to the single-channel current experiments we could see that the channel molecules through "channel" mechanism to achieve the ion transport across the membrane.After further experiments,we demonstrated that the transport activity of this channel is closely related to the length of channels.In addition,the bioactivity experiments showed that the channel molecules can inhibit bacterial growth effectively,especially the compounds 2-4 and 2-5,which exhibited similiar antibacterial activity comparing with gramicidin A.In the second part,a class of unimolecule tubular channels composed of cyclic peptides has been desgined,and we have completed part of the synthesis work.The target molecules constructed using thecyclic peptide units,and which are connected through the covalent bond to form a tubular channel structure.The compound we currently proceed to the synthesis stage now.And we have achieved the derivatization of the cyclic peptides by introducing different functional groups,such as azide and alkyne used to click chemistry.The assembly of the target molecules and the channel activity tests will be continued by others in our laboratory.