| Cells can exhibit gating mechanisms after suffering external stimuli to achieve the function of material metabolism inside the cell,signal transmission and energy conversion.The transmembrane proteins is a kind of protein nanochannel named lipid biomolecular,which was embedded in biomembranes and forms the pathway of organism.However,the embedded biomimetic biological nanochannels in lipid bilayer may cause the physical chemistry being unstable and fragile,which limited the vitro applications of them.Therefore,the organic membranes based on artificial nanochannels were emerged,and can overcome these issues as a substitute.In the past few years,artificial nanochannel is facile chemical modification of the channel on the surface,owing to the easy control in shape and size,and the stability of chemical and mechanical,has attracted a lot of attentions in different scientific community.In previous studies,the nanochannel with different ionic or molecules response functions was made for the use of detection,transmission,and separation of small molecules.Chemical modification and self-assembly modification are generally used in fabrication artificial nanochannel,however,both of the methods were not satisfactory.In this paper,three main research was reported to solve the problem of stability,reversible circulation of proteins under the basis of controlled release of small molecules were also studied systematically.The research is as follows:(1)Inside a cell,glutathione(GSH)is the key molecule of mopping up free radicals,and can prevent the oxidation of substances by free radicals.The active site of GSH is outside the cell,thus,it is very important to study the membrane transport of behavior GSH.In the first project,the reactive disulfide bond based nanochannels were constructed to control the release of GSH by the combining host-guest system with covalent bond.Effects of different surface charge density of channels on qualitative and quantitative experiments of GSH transport and release in mercapto-ethylamine pillar[5]arene(MEP5)/GSH channel and MEP5/GSSG channel.The flux of MEP5/GSH channel is 22 times more than that of MEP5/GSH channel by calculating the flux of transmission release,and the channel achieves the characteristic of reversible circulation.According to our results,GSH displays higher transmission and release performance comparing with the acidic amino acids.This result provides a new idea in developing reactive nanochannel in the future.(2)We try to explore the possibility of the utilization of this system for protein transport.Since iron porphyrins are present in hemoglobin(Hb),the existence of GSH can prevent the oxidation process of ferrous ions.The nanochannel transport protein of living body is a process of adsorption and release,and the channel surface has a large nucleophilic effect on protein molecules,which is conducive to the protein entering the restricted space and completing the adsorption and release process.In our second project,PET membrane was used to fabricate reaction type disulfide bond nanochannel and realizes the transport behavior of Hb.At the same time,the quantitative and qualitative experiments of Hb transport in MEP5/GSH channel and MEP5/GSSG channel are carried out to realize the high-throughout transport performance of protein molecules in the confined space.Through the calculation of transmission flux,it shows that the flux of MEP5/GSH channel is 12.8 times more than that of MEP5/GSSG channel.These results provide a way to increase the flux of transport and achieve a reversible channel cycle through redox reactions.According to the result,Hb displays higher transport performance than other proteins,which proved the transfer performance of disulfide bond channel to protein molecule.(3)In the living body,several kinds of mechanical force sensitive channels can be opened or closed by pressure.The behavior of controlling and releasing a molecular in our previous work was achieved under voltage driver.But the method of voltage driver could not apply to industrial production,in order to achieve protein separation,pressure was used as a driving force.Firstly,Hb molecule was selectively isolated from Albumin from bovine serum(BSA)and ovalbumin(OVA).Secondly,the disulfide-bonded function nanochannels were constructed and the proteins were separated by the affinity interaction of GSH.Finally,according to the result,the binding ratio of GSH to three protein molecules is 1:1,and the binding constant of GSH and Hb possessed the highest value.The primary separation of HB in MEP5/GSH channel was demonstrated by the result of confocal fluorescence and contact angle.Hence,the method of pressure separation provides a new idea for protein separation. |
PDF Full Text Request