Molecular Simulation Study of Feruloyl Esterase Adsorption on Charged Surfaces: Effects of Surface Charge Density and Ionic Strength

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• 作者：Jie Liu ; Chunwang Peng ; Gaobo Yu ; Jian Zhou
• 刊名：Langmuir
• 出版年：2015
• 出版时间：October 6, 2015
• 年：2015
• 卷：31
• 期：39
• 页码：10751-10763
• 全文大小：1092K
• ISSN：1520-5827

文摘

The surrounding conditions, such as surface charge density and ionic strength, play an important role in enzyme adsorption. The adsorption of a nonmodular type-A feruloyl esterase from Aspergillus niger (AnFaeA) on charged surfaces was investigated by parallel tempering Monte Carlo (PTMC) and all-atom molecular dynamics (AAMD) simulations at different surface charge densities (卤0.05 and 卤0.16 C路m^鈥?) and ionic strengths (0.007 and 0.154 M). The adsorption energy, orientation, and conformational changes were analyzed. Simulation results show that whether AnFaeA can adsorb onto a charged surface is mainly controlled by electrostatic interactions between AnFaeA and the charged surface. The electrostatic interactions between AnFaeA and charged surfaces are weakened when the ionic strength increases. The positively charged surface at low surface charge density and high ionic strength conditions can maximize the utilization of the immobilized AnFaeA. The counterion layer plays a key role in the adsorption of AnFaeA on the negatively charged COOH-SAM. The native conformation of AnFaeA is well preserved under all of these conditions. The results of this work can be used for the controlled immobilization of AnFaeA.