静磁场对猪胰脏脂肪酶催化活性和结构的影响研究

Influence of Static Magnetic Field on the Catalytic Activity and Structure of Lipase from Porcine Pancreas

将来源于猪胰脏的脂肪酶置于0.45 T强度的静磁场中,在不同温度、不同p H值条件下测定脂肪酶的催化活性,并且对米氏常数、酶蛋白二次结构进行测定,探索低成本方法以提高生物酶的催化活性.实验发现,在磁场存在的情况下,磁化2 h后的脂肪酶的催化活性明显提高.脂肪酶的最佳反应温度和最佳p H值没有因为磁化处理而改变.米氏常数Km和酶促反应最大速度Vmax均发生变化,磁化处理后的酶催化效率高于空白对照组.脂肪酶的构象在经过磁场处理后发生明显变化.

It was highly interest to tune the catalytic activity of enzymes in a convenient and low cost means. Herein, lipase was studied in the presence and absence of a 0.45 T static magnetic field.Enzymatic activities at varied exposure time, pH and temperature were assessed, together with the kinetic parameters of the cataly-sis and the secondary conformation.In the presence of the static magnetic field, the optimal exposure time is 2 h at which enhanced activity was observed while the optimal pH and temperature forthe catalytic reaction are unchanged.The Km decreased and Vmax also increased.Such behavior could be explained by the slight struc-ture change induced by the magnetic field as revealed by circular dichroism.