Molecular Insight Into The Effect Of Y220C Mutation On The Structural Stability Of P53C And Its Inhibitor Screening

The p53 tumor suppressor are the most frequently observed genetic mutation that have an important role to keep cell away from cancer.It is inactivated by mutation account for over half of human cancers.About one-third of the mutations are structural mutations that lower the melting temperature and unfold the p53 protein.The mutant Y220 C is unstable in conformationlly due to it forms a cavity in surface of p53 core domain.In this study,we performed molecular dynamics simulation to study the global structural changes of wild type p53 C and p53C-Y220 C.There is little difference of the stability of overall proteins structure between the two proteins.But the Y220 C cluster is unstable in comparison to the wild type p53 C.Further analysis indicates that intermolecular forces changes among amino acid residues and the changes of surface hydrophilicity for mutant Y220 C lead to changes of secondary structure,then destabilizing the global structure of p53C-Y220 C.This simulation reveals conformational effects of the Y220 C mutation and show us detailed insight for rescue the mutant Y220 C.In order to obtain the effective stabilizer,Lipinski's rule of five and docking method were successively used for virtual screening the DrugBank 4.0 library and we have found 3 candidate compounds.Then,all-atom molecular dynamics(MD)simulations were used to verify the affinity between these 3 molecules and the target protein.The simulations indicated that only tacrine bind tightly to the pocket and the complex remains stable.The affinity between tacrine and the target protein was further analyzed.It is found that the interactions between tacrine and the target protein are mainly hydrophobic and electrostatic interactions.And,the hydrophobic interactions are dominant force.Moreover,there are 3 hydrogen bonds between tacrine and residues Leu145,Asp228 and Val147 of the p53 C mutant Y220 C.Finally,the detailed binding process of tacrine and p53 C mutant Y220 C is probed based on MD simulations.Herein,the endogenous fluorescence,ThT fluorescence methods were used to investigate aggregation kinetics characteristics of p53C-Y220 C and validate the effectiveness of EGCG and tarcine.ThT fluorescence and TEM showed that EGCG could inhabit aggregation of p53C-Y220 C protein.In addition,p53C-Y220 C protein formed particle aggregation at 37 °C.