title: The cellulose-binding domain of cellobiohydrolase Cel7A from Trichoderma reesei is also a thermostabilizing domain.
abstract: The thermostability of cellobiohydrolase I Cel7A from Trichoderma reesei was investigated using dynamic light scattering. While the whole enzyme displayed a melting point of 59°C, the catalytic domain obtained via papain-catalyzed proteolysis was shown to denature at 51°C and the cellulose-binding domain (with linker attached) melted at 65-66°C. This variation in individual melting temperatures is proposed to account for the full retention of binding capacity of Cel7A at 50°C, along with a loss of catalytic activity observed for the catalytic domain alone. Thus, the cellulose-binding domain of Cel7A acts as a thermostabilizing domain for the enzyme. The effect of reducing agents on the protein melting behavior was also investigated.
authors.affiliation: School of Chemical & Biomolecular Engineering, Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332-0363, USA.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Hall
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rubin
authors.forename: Sven H
authors.initials: SH
authors.lastname: Behrens
authors.forename: Andreas S
authors.initials: AS
authors.lastname: Bommarius
mesh_terms: D001665:Binding Sites; D002384:Catalysis; D020134:Catalytic Domain; D002482:Cellulose / Q000737:chemistry*; D043366:Cellulose 1,4-beta-Cellobiosidase / Q000737:chemistry*; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry*; D006868:Hydrolysis; D007700:Kinetics; D059748:Proteolysis; D014242:Trichoderma / Q000201:enzymology*
chemical_list: D005656:Fungal Proteins; D002482:Cellulose; D043366:Cellulose 1,4-beta-Cellobiosidase