Molecular Mechanisms Underlying Inhibitory Binding of Alkylimidazolium Ionic Liquids to Laccase.

ABSTRACT: Water-miscible alkylimidazolium ionic liquids (ILs) are "green" co-solvents for laccase catalysis, but generally inhibit enzyme activity. Here, we present novel insights into inhibition mechanisms by a combination of enzyme kinetics analysis and molecular simulation. Alkylimidazolium cations competitively bound to the T_I Cu active pocket in the laccase through hydrophobic interactions. Cations with shorter alkyl chains (C₂~C₆) entered the channel inside the pocket, exhibiting a high compatibility with laccase (competitive inhibition constant K_ic = 3.36~3.83 mM). Under the same conditions, [Omim]Cl (K_ic = 2.15 mM) and [Dmim]Cl (K_ic = 0.18 mM) with longer alkyl chains bound with Leu296 or Leu297 near the pocket edge and Leu429 around T_I

SUBMITTER: Sun J 

PROVIDER: S-EPMC6152407 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature