Biofuels Institute, School of Emergency Management, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China.
Department of Biotechnology, Dr. Umayal Ramanathan College for Women, Algappapuram, Karaikudi 630003, Tamil Nadu, India.
Int J Biol Macromol. 2023 Dec 31;253(Pt 4):127117. doi: 10.1016/j.ijbiomac.2023.127117. Epub 2023 Sep 27.
Although dye-decolourising peroxidases (DyPs) are well-known for lignin degradation, a comprehensive understanding of their mechanism remains unclear. Therefore, studying the mechanism of lignin degradation by DyPs is necessary for industrial applications and enzyme engineering. In this study, a dye-decolourising peroxidase (CsDyP) gene from C. serinivorans was heterologously expressed and studied for its lignin degradation potential. Molecular docking analysis predicted the binding of 2, 2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), veratryl alcohol (VA), 2, 6-dimethylphenol (2, 6- DMP), guaiacol (GUA), and lignin to the substrate-binding pocket of CsDyP. Evaluation of the enzymatic properties showed that CsDyP requires pH 4.0 and 30 °C for optimal activity and has a high affinity for ABTS. In addition, CsDyP is stable over a wide range of temperatures and pH and can tolerate 5.0 mM organic solvents. Low NaCl concentrations promoted CsDyP activity. Further, CsDyP significantly reduced the chemical oxygen demand decolourised alkali lignin (AL) and milled wood lignin (MWL). CsDyP targets the β-O-4, CO, and CC bonds linking lignin's G, S, and H units to depolymerize and produce aromatic compounds. Overall, this study delivers valuable insights into the lignin degradation mechanism of CsDyP, which can benefit its industrial applications and lignin valorization.
虽然染料脱色过氧化物酶（DyPs）因木质素降解而广为人知，但对其机制仍缺乏全面了解。因此，研究 DyPs 降解木质素的机制对于工业应用和酶工程都是必要的。在本研究中，异源表达了来自 C. serinivorans 的一种染料脱色过氧化物酶（CsDyP）基因，并研究了其木质素降解潜力。分子对接分析预测了 ABTS、藜芦醇（VA）、2,6-二甲基苯酚（2,6-DMP）、愈创木酚（GUA）和木质素与 CsDyP 底物结合口袋的结合。酶学性质评价表明，CsDyP 需要 pH 4.0 和 30°C 才能达到最佳活性，并且对 ABTS 具有高亲和力。此外，CsDyP 在较宽的温度和 pH 范围内稳定，并且可以耐受 5.0 mM 的有机溶剂。低浓度的 NaCl 促进了 CsDyP 的活性。此外，CsDyP 显著降低了碱木质素（AL）和木粉木质素（MWL）的化学需氧量脱色。CsDyP 靶向连接木质素 G、S 和 H 单元的β-O-4、CO 和 CC 键，以解聚并产生芳香族化合物。总体而言，本研究深入了解了 CsDyP 降解木质素的机制，这将有益于其工业应用和木质素增值。
