Chemical Engineering Department, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia.
CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Int J Biol Macromol. 2024 Oct;277(Pt 4):134443. doi: 10.1016/j.ijbiomac.2024.134443. Epub 2024 Aug 12.
Laccases hold great potential for biotechnological applications, particularly in environmental pollutant remediation. Laccase activity is governed by the solvent environment, and ionic liquids (ILs) emerge as a versatile solvent for activation or stabilization of enzymes. Herein, effects of cholinium-based ILs formulated with carboxylic acids, inorganic acid, and amino acids as anionic species, on the catalytic activity of laccase from Trametes versicolor were investigated by experimental and computational approaches. Experimental results showed that laccase activity was enhanced by 21.39 % in 0.5 M cholinium dihydrogen citrate ([Cho][DHC]), in relation to the laccase activity in phosphate buffer medium. However, cholinium aminoate ILs negatively affected laccase activity, as evidenced by the partial deactivation of laccase in both cholinium glycinate and cholinium phenylalaninate, at concentrations of 0.1 M and 0.5 M, respectively. Molecular dynamics studies revealed that the enhancement of laccase activity in [Cho][DHC] might be attributed to the highly stabilized and compact structure of laccase, facilitating a better internal electron transfer during the laccase-substrate interactions. Enhanced catalytic performance of laccase in [Cho][DHC] was postulated to be driven by the high accumulation level of dihydrogen citrate anions around laccase's surface. [Cho][DHC] holds great promise as a cosolvent in laccase-catalyzed biochemical reactions.
漆酶在生物技术应用中具有巨大的潜力，特别是在环境污染物修复方面。漆酶的活性受溶剂环境的影响，离子液体（ILs）作为一种多功能溶剂，可以激活或稳定酶。本文通过实验和计算方法研究了含有羧酸、无机酸和氨基酸作为阴离子的胆碱基离子液体对变色栓菌漆酶催化活性的影响。实验结果表明，与磷酸盐缓冲介质中的漆酶活性相比，在 0.5 M 胆碱二氢柠檬酸盐（[Cho][DHC]）中漆酶活性提高了 21.39%。然而，胆碱氨基酸 ILs 对漆酶活性有负面影响，这可以从 0.1 M 和 0.5 M 甘氨酸胆碱和苯丙氨酸胆碱中漆酶的部分失活得到证明。分子动力学研究表明，[Cho][DHC]中漆酶活性的增强可能归因于漆酶高度稳定和紧凑的结构，这有助于在漆酶-底物相互作用过程中更好地进行内部电子转移。推测[Cho][DHC]能够作为漆酶催化生化反应的共溶剂，从而提高漆酶的催化性能。
