title: Imaging and measuring single-molecule interaction between a carbohydrate-binding module and natural plant cell wall cellulose.
abstract: The affinitive interaction between a carbohydrate-binding module (CBM3a) and natural crystalline cellulose was visualized and measured at the single-molecule level. Noncontact high resolution imaging by atomic force microscopy (AFM) was used to follow the binding process, in real time, of CBM3a-functionalized 6 nm gold nanoparticles (GNPs) to the cell wall polymers on poplar stem sections. The GNP-CBM3a complexes were found to bind to the cellulose surface, closely aligning along the cellulose fibril axis. The binding details were further confirmed and studied by single-molecule recognition imaging and AFM single-molecule dynamic force spectroscopy (SMDFS) using a CBM3a-functionalized AFM tip. The unbinding force was measured to be 44.96 ± 18.80 pN under a loading rate of 67.2 nN/s. This research provides a radical method for the study of single-molecule affinity between CBM and cellulose that is critical to the engineering of novel cellulolytic enzymes.
authors: Single Molecule Study Laboratory, Faculty of Engineering and Nanoscale Science and Engineering Center, University of Georgia, Athens, Georgia 30602, USA.
authors: Mengmeng
authors: M
authors: Zhang
authors: Sheng-Cheng
authors: SC
authors: Wu
authors: Wen
authors: W
authors: Zhou
authors: Bingqian
authors: B
authors: Xu
mesh_terms: D001665:Binding Sites; D002241:Carbohydrates / Q000737:chemistry*; D002473:Cell Wall / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D048013:Acetivibrio thermocellus / Q000737:chemistry / Q000235:genetics; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D032107:Populus / Q000737:chemistry* / Q000166:cytology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D013499:Surface Properties
chemical_list: D002241:Carbohydrates; D011994:Recombinant Proteins; D006046:Gold; D002482:Cellulose