Related Experiment Video
Updated: Aug 17, 2026
High Throughput Screening of Fungal Endoglucanase Activity in Escherichia coli
Published on: August 13, 2011
Mode of action and substrate specificity of a purified exo-1,4-beta-D-glucosidase cloned from the cellulolytic
C E Ware1, A H Lachke, K Gregg
1Department of Biochemistry, Microbiology and Nutrition, University of New England, Armidale, Australia.
Abstract:
A gene encoding exo-1,4-beta-D-glucosidase, from Ruminococcus albus AR67, was cloned in Escherichia coli, restriction mapped, and shown to be expressed from sequences within the insert that function as a promoter in E. coli. The cloned enzyme was located predominantly in the cytoplasm (40%) and attached to insoluble cell components (48%). After purification to homogeneity, the enzyme (Mr = 64,000, monomeric) was specific for substrates with beta-D-glucopyranosyl configuration and was inactive against alpha-glucosides, lactosides and xylosides. Km values of the enzyme decreased with increasing chain length (G2-G5). Glucose was the major product of hydrolysis from cellodextrins. Preference for longer chain cellodextrins is consistent with exo-1,4-beta-D-glucan glucohydrolase mode of action [E.C. 3.2.1.74].
