研究了压力、保压时间、pH值等对脂肪酶活性的影响,并且通过圆二色光谱和内源荧光光谱研究了脂肪酶的构象变化。结果表明,经过70℃、pH 7.5、压力200 MPa、保压时间15 min的处理后,脂肪酶的酶活力比常压对照提高了32%;200 MPa下,随着保压时间延长,脂肪酶活性较稳定,相对酶活性均保持在120%以上;最适pH增加了0.5个单位。光谱分析显示,高压处理后,脂肪酶二级结构中α-螺旋含量明显升高,β-折叠含量降低,内源荧光中的色氨酸特征峰的荧光强度增强10%～20%。

The paper reported the effects of the pressure,the dwell time and pH on the lipase activity,and focused on the changes of the lipase conformation through the Circular Dichroism(CD) spectroscopy and endogenous fluorescence spectroscopy.The main results were discussed as follows: In comparison with atmospheric pressure,the lipase activity under 200 MPa was increased by 32% at 70℃,pH7.5,15 min: With the extension of the dwell time,the lipase activity was stabilized,and the relative activities stayed above 120%.The optimal pH increased by 0.5.CD spectroscopy revealed that after high pressure treatment the secondary structure of lipase had changed,α-helix content increased significantly,β-sheet content decreased and endogenous fluorescence spectroscopy showed tryptophan characteristic peak rised by 10%～20%.