Synthesis And Biomedical Application Of Site-Specific And Topological IFN?-Poly(Amino Acid) Conjugates

The human recombination interferon is a kind of protein drugs which can perform anti-tumor and anti-virus roles.When this drug is administered in vivo,we have to face its biggest problem,i.e.the short half-life originating from the liver's elimination and the protease's degradation.Some modifications have been done to solve this defect.For example,PEG is linked to this protein to enhance the stability,however,some problems are still existing,including non-specific modification,strong immunogenic and the toxicity caused by the non-degradable PEG.Therefore,it's urgent to find the more suitable alternative polymer materials for the protein modification.In this article,we choose poly(amino acid)(PAA)to covalently modify the human recombination interferon.PAA has several merits that make it prefect polymer materials for the protein modifications,such as the biodegradability of the main chain,the convenience of modification to the side chain and selective reactivity of the terminal group.Native chemical ligation and sortaseA-mediated ligation raction happenned between protein and one special PAA carring one thioester bond to produce the linear and circular conjugates.After confirmed by the mass and western-blotting,we use the fluorescence spectrum and CD spectrum to test the conjugates' stability,Elisa method was also used to track the pharmacokinetics and the tissue distribution.On the other hand,we test the conjugates' anti-tumor activity,the anti-virus activity and immunogenic in vitro and in vivo.From the above results,we can find that:(1)the linear and circular conjugates we synthesized in vitro have the bigger hydrodynamic size than the wild type,thermostability and protease resistance are enhanced also;(2)the synthesized conjugates still remained some anticancer and anti-virus activities whilst the immunogenic property was not affected significantly;(3)the conjugates performed anticaner activity in vivo experiment probably due to the longer lifetime in blood cirulation and higher specificity for tissue distribution.This work will provide some guidance for the further systematic studies on the IFN-PAAs conjugates.