Exploring how lignin structure influences the interaction between carbohydrate-binding module and lignin using AFM

Hui Chen; Bo Jiang; Chunyang Zou; Zhichao Lou; Junlong Song; Wenjuan Wu; Yongcan Jin

doi:10.1016/j.ijbiomac.2023.123313

Exploring how lignin structure influences the interaction between carbohydrate-binding module and lignin using AFM

Int J Biol Macromol. 2023 Mar 31:232:123313. doi: 10.1016/j.ijbiomac.2023.123313. Epub 2023 Jan 20.

Authors

Hui Chen¹, Bo Jiang¹, Chunyang Zou², Zhichao Lou³, Junlong Song¹, Wenjuan Wu⁴, Yongcan Jin⁵

Affiliations

¹ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing 210037, China; Joint International Research Lab of Lignocellulosic Functional Materials, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
² Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing 210037, China.
³ Joint International Research Lab of Lignocellulosic Functional Materials, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.
⁴ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing 210037, China. Electronic address: wenjuanwu@njfu.edu.cn.
⁵ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing 210037, China; Joint International Research Lab of Lignocellulosic Functional Materials, International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China. Electronic address: jinyongcan@njfu.edu.cn.

PMID: 36682668
DOI: 10.1016/j.ijbiomac.2023.123313

Abstract

Nonproductive adsorption of cellulase onto the residual lignin in substrate seriously hinders the enzymatic hydrolysis. To understand how lignin structure affects lignin-cellulase interaction, the carbohydrate-binding module (CBM) functionalized atomic force microscope tip was used to measure CBM-lignin interaction by single-molecule dynamic force spectroscopy in this work. The results showed that sulfonated lignin (SL) has the greatest adhesion force to CBM (4.74 nN), while those of masson pine milled wood lignin (MWL), poplar MWL and herbaceous MWLs were 2.85, 1.03 and 0.27-0.61 nN, respectively. It provides direct quantitative evidence for the significance of lignin structure on lignin-cellulase interaction. The CBM-MWLs interaction decreased sharply to 0.054-0.083 nN while SL was added, indicating the primary mechanism of SL promoting lignocellulose hydrolysis was significantly reducing the nonproductive adsorption of substrate lignin on cellulase. Finally, the "competitive adsorption" mechanism was proposed to interpret why SL effectively promotes the enzymatic hydrolysis of lignin-containing substrates.

Keywords: Carbohydrate-binding module (CBM); Lignin; Single-molecule interaction.

MeSH terms

Adsorption
Carbohydrates
Cellulase* / chemistry
Hydrolysis
Lignin / chemistry
Trichoderma*

Substances

Lignin
Cellulase
Carbohydrates