College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China.
Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, China.
Bioprocess Biosyst Eng. 2018 Mar;41(3):331-343. doi: 10.1007/s00449-017-1866-z. Epub 2017 Nov 28.
The biodegradation of nonylphenol (NP) and octylphenol (OP) isomers by laccase has attracted increasing concerns. However, the interaction mechanism between these isomers and laccase remains unclear, especially for fungal laccase. In this work, molecular docking was employed to study this issue. The results indicated that the structural characteristic of alkyl chain (position and branching degree) affected the interactions between Trametes versicolor (T. versicolor) laccase and isomers. The binding affinity between them was closely related to the position and branching degree of alkyl chain in isomers. The binding affinities between linear isomers and T. versicolor laccase were para-position < meta-position < ortho-position. For selected branched 4-NP, the isomers with bulky α-substituent in alkyl chain had higher binding affinities. In addition, hydrophobic contacts between T. versicolor laccase and NP or OP isomers were necessary, while H-bonds were optional. The isomers with similar structure may have more common residues involved in hydrophobic contacts. The H-bonds of selected NPs and OPs were all connected with phenolic hydroxyl. These findings provide an insight into detailed interaction mechanism between T. versicolor laccase and isomers of NP and OP. It is helpful to broaden the knowledge of degradation technology of NPs and OPs and provide theoretical basis on biological remediation of these contaminants.
酶促降解壬基酚（NP）和辛基酚（OP）异构体引起了越来越多的关注。然而，这些异构体与漆酶之间的相互作用机制仍不清楚，特别是对于真菌漆酶。在这项工作中，采用分子对接研究了这一问题。结果表明，烷基链的结构特征（位置和支化度）影响了糙皮侧耳（T. versicolor）漆酶与异构体之间的相互作用。它们之间的结合亲和力与异构体中烷基链的位置和支化度密切相关。直链异构体与 T. versicolor 漆酶的结合亲和力为对位<间位<邻位。对于选定的支化 4-NP，烷基链中具有较大α取代基的异构体具有更高的结合亲和力。此外，T. versicolor 漆酶与 NP 或 OP 异构体之间需要疏水接触，而氢键是可选的。结构相似的异构体可能具有更多共同的残基参与疏水接触。所选 NPs 和 OPs 的氢键均与酚羟基相连。这些发现深入了解了 T. versicolor 漆酶与 NP 和 OP 异构体之间的详细相互作用机制。它有助于拓宽 NPs 和 OPs 降解技术的知识，并为这些污染物的生物修复提供理论依据。
