Abstract
Cellobiohydrolase-I (CBH I), a processive exoglucanase secreted by Trichoderma reesei, is one of the key enzyme components in a commercial cellulase mixture currently used for processing biomass to biofuels. CBH I contains a family 7 glycoside hydrolase catalytic module, a family 1 carbohydrate-binding module (CBM), and a highlyglycosylated linker peptide. It has been proposed that the CBH I cellulase initiates the hydrolysis from the reducing end of one cellulose chain and successively cleaves alternate β-1,4-glycosidic bonds to release cellobiose as its principal end product. The role each module of CBH I plays in the processive hydrolysis of crystalline cellulose has yet to be convincingly elucidated. In this report, we use a single-molecule approach that combines optical (Total Internal Reflection Fluorescence microscopy, or TIRF-M) and non-optical (Atomic Force Microscopy, or AFM) imaging techniques to analyze the molecular motion of CBM tagged with green fluorescence protein (GFP), and to investigate the surface structure of crystalline cellulose and changes made in the structure by CBM and CBH I. The preliminary results have revealed a confined nanometer-scale movement of the TrCBM1-GFP bound to cellulose, and decreases in cellulose crystal size as well as increases in surface roughness during CBH I hydrolysis of crystalline cellulose.
Original language | American English |
---|---|
Number of pages | 8 |
DOIs | |
State | Published - 2010 |
Event | Single Molecule Spectroscopy and Imaging III - San Francisco, CA, United States Duration: 23 Jan 2010 → 25 Jan 2010 |
Conference
Conference | Single Molecule Spectroscopy and Imaging III |
---|---|
Country/Territory | United States |
City | San Francisco, CA |
Period | 23/01/10 → 25/01/10 |
NREL Publication Number
- NREL/CP-270-48502
Keywords
- AFM
- Carbohydrate-binding module (CBM)
- Cellobiohydrolase (CBH I)
- Cellulose
- Single molecule spectroscopy
- TIRF