Stereoselective hydrolysis catalyzed by a Bacillus endoglucanase in family D.

An endoglucanase in family D, purified from a strain of Bacillus, was found to catalyze the hydrolysis of p-nitrophenyl beta-D-cellotrioside to generate alpha-cellobiose, as determined by 1H-NMR spectroscopy. The hydrolysis of the beta-1,4 glucosidic bond by the enzyme proceeds, therefore, by an inversion mechanism. Furthermore, the interconversion of the alpha- and beta-anomeric protons in the products of hydrolysis, after equilibrium had been reached by mutarotation, was directly characterized by magnetization transfer NMR experiment that exploited the truncated driven nuclear Overhauser effect.