Molecular Dynamics Simulation Of The Effect Of Hydrophilic And Hydrophobic Amino Acid Mutation On The Structural Stability Of 2709 Protease

2709 protease is an important industrial enzyme,which has been widely used in industry and scientific research.Generally,2709 protease is prone to hydrolysis and deamidation reactions in aqueous solutions,resulting in its instability in aqueous solutions,which to some extent affects its structural properties.Currently,the research on the structure of 2709 protease is only limited to its primary structure,and the analysis of its three-dimensional structure is not clear,which will limit the application of 2709 protease in many fields.Based on this,the three-dimensional structure of 2709 protease was constructed using homologous modeling technology,and the rationality of the structure was evaluated by comparison,and the obtained three-dimensional structure was put into a water box for molecular dynamics simulation up to 300 ns.The suitable mutation sites were selected and six hydrophobic and hydrophilic amino acid mutants were generated.Molecular dynamics simulation of 2709 protease mutant was continued,and the 2709 protease mutant with improved stability was found.The results show that the 2709 three-dimensional structure model constructed by homologous modeling is reasonable and can be used for simulation research.During the simulation of 2709 protease in aqueous solution,asparagine No.61,160 and 211 are more flexible in aqueous solution,and can mutate hydrophilic and hydrophobic amino acids at these three sites.The results show that the three-dimensional structural model constructed by homologous modeling of 2709 protease is reasonable and can be used for simulation research.During the simulation process of 2709 protease in aqueous solution,asparagine 61,160,and 211 have greater flexibility in aqueous solution,and can undergo hydrophilic and hydrophobic amino acid mutations at these three sites,resulting in six mutants 2709(N61G),2709(N160G),2709(N211G),2709(N61S),2709(N160S),and 2709(N211S).Secondly,by analyzing the changes in the RMSD,Rg,RMSF,SASA,secondary structure,and hydrogen bonds of the six mutants during the simulation process,it was found that the hydrophilic amino acid mutation had a better effect on improving the stability of the 2709 protease than the hydrophobic amino acid mutation.Among hydrophilic amino acid mutants,mutant 2709(N211S)has the best mutation effect.Its stability is improved both in terms of overall conformation and amino acid residues,and the hydrogen bond interaction between amino acid residues within the protease molecule is also strengthened,which further stabilizes the conformation of the protease and improves the stability of 2709 protease in aqueous solution.The results of the study identified a 2709 protease mutant 2709(N211S)with significantly improved stability.This provides a theoretical basis for future research on protease stability modification.