Carbohydrate-binding modules recognize fine substructures of cellulose.
Competition isotherms are used to identify the set of cellulose substructures to which cellulose binding modules (CBMs) from families 2a, 3, 4, 9, and 17 bind. The experiments are based on coupling a unique fluorescent tag to each CBM in a manner that does not alter the natural binding properties of the CBM and therefore allows the surface and solution concentrations of each CBM to be monitored as a function of time and composition. Adsorption and surface exchange of like or competing CBMs are monitored using a range of cellulose preparations varying in both crystallinity and provenance. CBMs from families 2a, 3, 4, 9, and 17 are shown to recognize different physical forms of prepared cellulose. The demonstration of the very fine binding specificity of cellulose-specific CBMs implies that the polysaccharide targets of CBMs extend down to the resolution of cellulose microstructures.
McLean
Bradley W
BW
Protein Engineering Network of Centres of Excellence, PENCE Inc., National Business Centre, Edmonton, Alberta T6G 2S2, Canada.
Boraston
Alisdair B
AB
Brouwer
Darren
D
Sanaie
Nooshafarin
N
Fyfe
Colin A
CA
Warren
R Antony J
RA
Kilburn
Douglas G
DG
Haynes
Charles A
CA
D001665:Binding Sites; D001667:Binding, Competitive; D002241:Carbohydrates / Q000737:chemistry; D002480:Cellulase / Q000378:metabolism; D002482:Cellulose / Q000737:chemistry* / Q000378:metabolism; D003460:Crystallization; D007700:Kinetics; D013058:Mass Spectrometry; D014961:X-Ray Diffraction; D043325:Xylan Endo-1,3-beta-Xylosidase; D014995:Xylosidases / Q000378:metabolism
D002241:Carbohydrates; D002482:Cellulose; D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase; D002480:Cellulase