School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, PR China.
Ultrason Sonochem. 2011 Jan;18(1):419-24. doi: 10.1016/j.ultsonch.2010.07.014. Epub 2010 Jul 27.
This research was to explore the mechanism of ultrasonic impact on protease activity. The effects of energy-gathered ultrasound on the activity, kinetics, thermodynamics and molecular structure of Alcalase were investigated with the aid of the chemical reaction kinetics model, Arrhenius equation, Eyring transition state theory, fluorescence spectroscopy and circular dichroism (CD) spectroscopy. Results showed that ultrasound had effect on the activity of Alcalase. The highest Alcalase activity was achieved when the sample was treated with energy-gathered ultrasound at 80 W for 4 min, under which the enzyme activity was increased by 5.8% over the control. After the treatment, thermodynamics parameters Ea, ΔH, ΔS and ΔG were reduced by 70.0%, 75.8%, 34.0% and 1.3%, respectively. Besides, fluorescence and CD spectra revealed that the ultrasonic treatment had increased the number of tryptophan on Alcalase surface slightly, increased number of α-helix by 5.2%, and reduced the number of random coil by 13.6%.
本研究旨在探讨超声冲击对蛋白酶活性的作用机制。采用化学反应动力学模型、阿仑尼乌斯方程、艾林过渡态理论、荧光光谱和圆二色性（CD）光谱等方法，研究了聚能超声对碱性蛋白酶活性、动力学、热力学和分子结构的影响。结果表明，超声对碱性蛋白酶的活性有影响。当样品在 80 W 下聚能超声处理 4 分钟时，碱性蛋白酶的活性最高，比对照提高了 5.8%。处理后，热力学参数 Ea、ΔH、ΔS 和 ΔG 分别降低了 70.0%、75.8%、34.0%和 1.3%。此外，荧光和 CD 光谱表明，超声处理使碱性蛋白酶表面的色氨酸数量略有增加，α-螺旋增加了 5.2%，无规卷曲减少了 13.6%。
