Beta-glucosidase
Encyclopedia
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.
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
or glucose-substituted molecules (i.e., the disaccharide
Disaccharide
A disaccharide or biose is the carbohydrate formed when two monosaccharides undergo a condensation reaction which involves the elimination of a small molecule, such as water, from the functional groups only. Like monosaccharides, disaccharides form an aqueous solution when dissolved in water...
cellobiose
Cellobiose
Cellobiose is a disaccharide with the formula [HOCH2CHO3]2O. Cellobiose consists of two glucose molecules linked by a β bond. It can be hydrolyzed to glucose enzymatically or with acid. Cellobiose has eight free alcohol groups, one acetal linkage and one hemiacetal linkages, which give rise to...
). 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
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....
is largely composed of polymers of beta-bond linked glucose molecules, and beta-glucosidases are required by organisms (some fungi, bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, termites) that can consume it. These enzymes are a powerful tool for degradation of plant cell walls for pathogens.
Lysozyme
Lysozyme
Lysozyme, also known as muramidase or N-acetylmuramide glycanhydrolase, are glycoside hydrolases, enzymes that damage bacterial cell walls by catalyzing hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in a peptidoglycan and between...
, 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
Peptidoglycan
Peptidoglycan, also known as murein, is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of bacteria , forming the cell wall. The sugar component consists of alternating residues of β- linked N-acetylglucosamine and N-acetylmuramic acid...
cell walls of gram-negative bacteria.
External links
- GO-database listing 'GO:0016162 cellulose 1,4-beta-cellobiosidase activity'