Maryam Ghorbani - Department of Chemistry, Ferdowsi University of Mashhad, International Campus, Mashhad, Iran
Mohammad Reza Housaindokht - Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
Mohammad Reza Bozorgmehr - Department of Chemistry, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad,Iran

Chloroperoxidase (CPO) a heme-thiolate protein secreted by the marine fungusCaldariomyces fumago, has received much attention as the most versatile known heme enzyme.The signature function of CPO is halogenation of electron-rich organic substrates [1]. IonicLiquids (ILs) containing solvents can change the structure, stability and function of proteins. Thestudy of protein conformation in ILs is important to understand enzymatic activity. In this work,conformational stability and activity of the enzyme in two imidazolium-based ILs (as 1-Butyl-3-methylimidazolium Bromide & 1-Butyl-3-methylimidazolium methyl sulfate) were investigated.Molecular dynamics (MD) simulations were performed by the GROMACS 4.5.6 package usingthe GROMOS96 43A1 force field [2]. Experimental studies have shown that ILs with certainconcentration increase the oxidation efficiency of this enzyme. The present study could improveour understanding of the molecular mechanism about the ionic liquid effects on the structure andactivity of proteins. Root mean square deviation (RMSD), root mean square fluctuation (RMSF)and protein secondary structure were evaluated in absence and present of the ILs.

Chloroperoxidase, Ionic Liquid, Molecular Dynamic Simulation