User:Boris Brumshtein: Difference between revisions
New page: == Acid-beta-glucosidase == Acid-beta-glucosidase is a lysozomal enzyme, which cleaves glucoceramide to glucose and ceramide. It acts through an acid-base hydrolysis. The enzyme, which ... |
No edit summary |
||
| Line 5: | Line 5: | ||
The enzyme, which acts through an [http://en.wikipedia.org/wiki/Acid-base_reaction acid-base mechanism] has to contain in the active site a proton donor, an acid, and a nuclophile, the base. The nuclophile is involved in formation and stabilization of the intermediate state, were a proton is transferred from an anomeric carbon to the leaving group. At that stage, the proton donor would donate its proton to the intermediate complex, releasing the second product and hence acting as a catalytic acid. Such a mechanism depends strongly on the pH of the environment. Fine changes in acidity of the solution might affect the ionization states of the residues involved in the catalysis. Therefore there would be a strong dependence of the enszyme's activity on the pH of the solution. | The enzyme, which acts through an [http://en.wikipedia.org/wiki/Acid-base_reaction acid-base mechanism] has to contain in the active site a proton donor, an acid, and a nuclophile, the base. The nuclophile is involved in formation and stabilization of the intermediate state, were a proton is transferred from an anomeric carbon to the leaving group. At that stage, the proton donor would donate its proton to the intermediate complex, releasing the second product and hence acting as a catalytic acid. Such a mechanism depends strongly on the pH of the environment. Fine changes in acidity of the solution might affect the ionization states of the residues involved in the catalysis. Therefore there would be a strong dependence of the enszyme's activity on the pH of the solution. | ||
Several x-ray structures of the enzyme have been solved. [http://www.pdb.org PDB] codes: [[1y7v]]; [[1ogs]]; [[2f61]]; [[2nt0]]; [[2nt1]]; [[2v3d]]; [[2v3e]]; [[2nsx]]; [[2j25]] | Several x-ray structures of the enzyme have been solved. [http://www.pdb.org PDB] codes: [[1y7v]]; [[1ogs]]; [[2f61]]; [[2nt0]]; [[2nt1]]; [[2v3d]]; [[2v3e]]; [[2nsx]]; [[2j25]] | ||
[[Image:gcase_scheme.jpg]] | |||
== Gaucher disease == | == Gaucher disease == | ||
[http://en.wikipedia.org/wiki/Gaucher's_disease Gaucher disease], the most common lysosomal storage disorder (LSD), is caused by mutations in the gene encoding acid-β-glucosidase ([http://www.chem.qmul.ac.uk/iubmb/enzyme/ enzyme classification] E.C. 3.2.1.45), resulting in intracellular accumulation of glucosylceramide (GlcCer). The protein consists of 497 amino acids with 5 putative glycosylation site (Mw ~60 kDa, pI~7.2), 4 of which are believed to be occupied. | [http://en.wikipedia.org/wiki/Gaucher's_disease Gaucher disease], the most common lysosomal storage disorder (LSD), is caused by mutations in the gene encoding acid-β-glucosidase ([http://www.chem.qmul.ac.uk/iubmb/enzyme/ enzyme classification] E.C. 3.2.1.45), resulting in intracellular accumulation of glucosylceramide (GlcCer). The protein consists of 497 amino acids with 5 putative glycosylation site (Mw ~60 kDa, pI~7.2), 4 of which are believed to be occupied. | ||
Revision as of 18:08, 14 November 2007
Acid-beta-glucosidaseAcid-beta-glucosidase
Acid-beta-glucosidase is a lysozomal enzyme, which cleaves glucoceramide to glucose and ceramide. It acts through an acid-base hydrolysis.
The enzyme, which acts through an acid-base mechanism has to contain in the active site a proton donor, an acid, and a nuclophile, the base. The nuclophile is involved in formation and stabilization of the intermediate state, were a proton is transferred from an anomeric carbon to the leaving group. At that stage, the proton donor would donate its proton to the intermediate complex, releasing the second product and hence acting as a catalytic acid. Such a mechanism depends strongly on the pH of the environment. Fine changes in acidity of the solution might affect the ionization states of the residues involved in the catalysis. Therefore there would be a strong dependence of the enszyme's activity on the pH of the solution. Several x-ray structures of the enzyme have been solved. PDB codes: 1y7v; 1ogs; 2f61; 2nt0; 2nt1; 2v3d; 2v3e; 2nsx; 2j25
Gaucher diseaseGaucher disease
Gaucher disease, the most common lysosomal storage disorder (LSD), is caused by mutations in the gene encoding acid-β-glucosidase (enzyme classification E.C. 3.2.1.45), resulting in intracellular accumulation of glucosylceramide (GlcCer). The protein consists of 497 amino acids with 5 putative glycosylation site (Mw ~60 kDa, pI~7.2), 4 of which are believed to be occupied.