Towle Zak, Cruickshank Faye, Mackay C Logan, Clarke David J, Horsfall Louise E
Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Roger Land Building, King's Buildings, Edinburgh, EH9 3FF, UK.
EaStCHEM School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, UK.
Analyst. 2024 Apr 15;149(8):2399-2411. doi: 10.1039/d4an00124a.
Lignin is a complex heteroaromatic polymer which is one of the most abundant and diverse biopolymers on the planet. It comprises approximately one third of all woody plant matter, making it an attractive candidate as an alternative, renewable feedstock to petrochemicals to produce fine chemicals. However, the inherent complexity of lignin makes it difficult to analyse and characterise using common analytical techniques, proving a hindrance to the utilisation of lignin as a green chemical feedstock. Herein we outline the tracking of lignin degradation by an alkaliphilic laccase in a semi-quantitative manner using a combined chemical analysis approach using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to characterise shifts in chemical diversity and relative abundance of ions, and NMR to highlight changes in the structure of lignin. Specifically, an alkaliphilic laccase was used to degrade an industrially relevant lignin, with compounds such as syringaresinol being almost wholly removed (95%) after 24 hours of treatment. Structural analyses reinforced these findings, indicating a >50% loss of NMR signal relating to β-β linkages, of which syringaresinol is representative. Ultimately, this work underlines a combined analytical approach that can be used to gain a broader semi-quantitative understanding of the enzymatic activity of laccases within a complex, non-model mixture.
木质素是一种复杂的杂环芳香聚合物，是地球上含量最丰富、种类最多样的生物聚合物之一。它约占所有木本植物物质的三分之一，这使其成为一种有吸引力的候选物，可作为石化产品的替代可再生原料来生产精细化学品。然而，木质素固有的复杂性使其难以用常规分析技术进行分析和表征，这对将木质素用作绿色化学原料构成了阻碍。在此，我们概述了使用傅里叶变换离子回旋共振质谱（FT-ICR MS）结合化学分析方法以半定量方式跟踪嗜碱漆酶对木质素的降解，该方法用于表征离子化学多样性和相对丰度的变化，并用核磁共振（NMR）突出木质素结构的变化。具体而言，使用一种嗜碱漆酶降解一种具有工业相关性的木质素，经过24小时处理后，诸如丁香树脂醇等化合物几乎被完全去除（95%）。结构分析强化了这些发现，表明与β-β键相关的核磁共振信号损失超过50%，丁香树脂醇就是其中的代表。最终，这项工作强调了一种组合分析方法，该方法可用于更全面地半定量了解复杂非模型混合物中漆酶的酶活性。
