在包含离子的液体( IL )的系统的马肝白酒脱氢酶( HLADH )的催化特征( BMIm ????????????????猠牵牰獥敳?????????€ 污敫敮刯?????????ǐ
The catalytic characteristics of horse liver alcohol dehydrogenase (HLADH) in the systems involving ionic liquids (ILs) (BMIm·Cl, BMIm·Br, BMIm·PF6, BMIm·BF4 BMIm·OTf and EMIm·Cl) were examined. HLADH displayed higher oxidation activity towards ethanol in the systems containing BMIm·Cl, BMIm·Br, EMIm·Cl or BMIm·PF6 with proper content than that in the IL-free buffer. An excessive amount of these ILs in the reaction systems resulted in an obvious decline in enzymatic activity. BMIm·BF4 and BMIm·OTf of any content investigated could considerably inhibit the enzyme. The anions of ILs showed significant effect on the activity, kinetic parameters and activation energy of HLADH-mediated ethanol oxidation. Additionally, BMIm·Cl, BMIm·Br, EMIm·Cl and BMIm·PF6 boosted markedly the thermostability of HLADH, while the enzyme was less thermostable in BMIm·BF4 or BMIm·OTf-containing systems. The associated conformational changes in HLADH caused by ILs were examined by UV technique.