Target type: cellularcomponent
A heterodimeric complex that catalyzes the trimming of glucose residues from N-linked core glycans on newly synthesized glycoproteins. [PMID:10464333, PMID:8910335]
Glucosidase II complex is a heterodimeric enzyme found in the endoplasmic reticulum (ER) lumen. It is composed of two subunits: GIIα and GIIβ. Both subunits are type I transmembrane proteins with their N-termini facing the ER lumen and their C-termini anchored to the ER membrane. GIIα is the catalytic subunit, responsible for hydrolyzing glucose residues from N-linked glycans on newly synthesized glycoproteins. GIIβ is a non-catalytic subunit that plays a regulatory role in the complex. It interacts with GIIα through its N-terminal domain, and this interaction is essential for the proper folding and function of GIIα.
GIIα contains two active sites, one at each end of the molecule, and these sites are accessible to the ER lumen. The active sites of GIIα are located within a deep cleft, which is lined by conserved residues that are essential for catalysis. GIIα is a highly specific enzyme that only removes glucose residues from N-linked glycans. It does not hydrolyze other types of sugars, such as mannose or galactose.
The glucosidase II complex is essential for the proper folding and maturation of glycoproteins in the ER. The enzyme removes glucose residues from N-linked glycans during glycoprotein folding, which allows for the formation of proper protein-protein interactions and the correct assembly of multi-subunit complexes. GII activity is tightly regulated, and its activity is modulated by a variety of factors, including the presence of chaperones, the availability of substrates, and the cellular environment.
In summary, the glucosidase II complex is a critical component of the ER protein folding machinery. It is responsible for removing glucose residues from N-linked glycans during glycoprotein folding, which is essential for the proper folding and maturation of glycoproteins.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| Neutral alpha-glucosidase AB | A neutral alpha-glucosidase AB that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q14697] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| cisapride | cisapride : The amide resulting from formal condensation of 4-amino-5-chloro-2-methoxybenzoic acid with cis-1-[3-(4-fluorophenoxy)propyl]-3-methoxypiperidin-4-amine. It has been used (as its monohydrate or as its tartrate) for the treatment of gastro-oesophageal reflux disease and for non-ulcer dyspepsia, but its propensity to cause cardiac arrhythmias resulted in its complete withdrawal from many countries, including the U.K., and restrictions on its use elsewhere. Cisapride: A substituted benzamide used for its prokinetic properties. It is used in the management of gastroesophageal reflux disease, functional dyspepsia, and other disorders associated with impaired gastrointestinal motility. (Martindale The Extra Pharmacopoeia, 31st ed) | benzamides | |
| 1-deoxynojirimycin | 1-deoxy-nojirimycin: structure in first source duvoglustat : An optically active form of 2-(hydroxymethyl)piperidine-3,4,5-triol having 2R,3R,4R,5S-configuration. | 2-(hydroxymethyl)piperidine-3,4,5-triol; piperidine alkaloid | anti-HIV agent; anti-obesity agent; bacterial metabolite; EC 3.2.1.20 (alpha-glucosidase) inhibitor; hepatoprotective agent; hypoglycemic agent; plant metabolite |
| labetalol hydrochloride | salicylamides |