The Study On Drug Screening Of Anti-Human Papillomavirus Components Targeting Human Papillomavirus Helicase

HPV(human papillomavirus)is a closed double-stranded circular DNA virus which has scarce therapy and can not be completely rid of the virus.Now the viable treatment means are vaccination which are not widely popularized and because of its high price.So clinical treatment need the drugs that have good effect based on a clear mechanism of drug action.Based on computer technology,the computer-aided drug screening is a way to design,optimize and screen small effective drug molecules by computer simulation,count and budget for the relationship between the drugs and receptor biological macromolecules.In our study,computer-aided drug screening mainly includes two aspects:first,molecular dynamics.It is a dynamic form to indicate the mode of action of receptor and ligand which mainly relies on Newtonian mechanics to simulate the movement of the molecular system.Second,molecular docking.Based on lock-key principle,it targets at receptor activity center to simulate the interaction between the receptor and small molecule ligands from a particular database for determining the degree of binding.The computer-aided drug screening narrows the scope of drug screening and is greatly contributed to the research and development of new drugs.In the viral DNA replication process,HPV E1 helicase open a closed double-stranded DNA structure to ensure the completion of the viral replication,so it is a key enzyme.Studies have shown that the biphenylsulfonacetic acid inhibitors of its helicase may be an effective role in HPV6 El protein tyrosine 486 residues to inhibit its activity,and this amino acid is highly conserved in the HPV family.Therefore,among the new anti-HPV drugs screening,we make the studies of computer-aided drug screening at HPV E1 helicase Y486.First,we made some studies on the inhibition mechanism of biphenylsulfonacetic acid for HPV helicase.With a molecular dynamics software NAMD and molecular docking software AutoDock4.2,we analyzed the binding of E1 protein and its reported inhibitor and found that the E1 RMSD(the root mean square deviation)value,protein secondary structure composition and length have some changes.It ensured that inhibitors change the structure of a protein to inhibit HPV helicase activity of the mechanism of action.With the analysis of the relationship between docking energy value and their IC50,we verify docking screening is a feasibility way of anti-HPV drugs.Second,we set natural products database(Supernatural Database)as the filter objects to screen HPV E1 helicase inhibitors.With comprehensive analysis in the toxicity of the compound,the free binding energy values,the stability and the mode of actions,we screened five compounds with strong binding capacity from 45,917 natural products.Final,for verifying the computer virtual screening effectiveness of the drug further,we get the plasmids with the HPV virus DNA from Harald zur Hausen experimental group.With conversion,extraction,agars gel electrophoresis and a series of experimental operation,we ensured the plasmid is required for our experiments which carry the HPV virus DNA plasmid and laid the foundation for the next step validation of the biological activity for screening drugs.In summary,in the use of molecular dynamics and molecular docking method,we identified that biphenylsulfonacetic acid inhibitor made allosteric action to inhibit the activity of HPV helicase.Then,we screened 5 compounds from natural products database which can be an effective role in the E1 protein helicase enzyme active center.At last,we verified the plasmids which carry HPV viral DNA.These studies laid the foundation for development of drugs for novel anti-human papillomavirus.