Site of hydrolysis of cellulodextrins and reduced cellulodextrins by purified cellulase components

Abstract

Abstract The mode of action of four electrophoretically distinct β-(1,4)-glucan hydrolases from Cellvibrio gilvus was studied by analysis of the intermediates and products of the hydrolysis of cellohexaose, reduced cellohexaose, and reduced cellopentoase. An analytical-scale procedure was described for simultaneous analysis of mixtures of the cellulodextrin polymer series and the reduced cellulodextrin polymer series from the monomer through the hexamer. No evidence of cleavage of the non-reducing terminal glucosyl bond was seen. Each of the hydrolases cleaved the second and third bonds from the non-reducing end with characteristic frequencies. No cleavage was observed at the fourth or fifth glucosyl bonds. A highly purified β-glucosidase (linear β-(1,4)-glucan 4-glucanohydrolase) from Aspergillus niger appeared to remove successive glucosyl moieties from the non-reducing end of the substrate. Acid hydrolysis indicated no selectivity in the site of cleavage.