Beta-glucosidase

Beta-glucosidase is a glucosidase enzyme that acts upon β1->4 bonds linking two glucose or glucose-substituted molecules (i.e., the disaccharide cellobiose). It is an exocellulase with specificity for a variety of beta-D-glycoside substrates. It catalyzes the hydrolysis of terminal non-reducing residues in beta-D-glucosides with release of glucose.

Cellulose is largely composed of polymers of beta-bond linked glucose molecules, and beta-glucosidases are required by organisms (some fungi, bacteria, termites) that can consume it. These enzymes are a powerful tool for degradation of plant cell walls for pathogens.

Lysozyme, an enzyme secreted in tears to prevent bacterial infection of the eye, is also a beta-glucosidase that cleaves β1→4 bonds between N-acetylglucosamine and N-acetylmuramic acid sugars within the peptidoglycan cell walls of gram-negative bacteria.