Endoplasmic reticulum alpha-glucosidase I (for α-glucosidase I) and Endoplasmic reticulum alpha-glucosidase II (for α-glucosidase II) (ER α-glucosidase I (for I), ER α-glucosidase II (for II))

Endoplasmic reticulum alpha-glucosidase I (GCSI) and alpha-glucosidase II (GCSII) are resident enzymes of the endoplasmic reticulum that catalyze sequential glucose trimming steps from the N-linked glycans on newly synthesized glycoproteins. α-Glucosidase I removes the outermost (terminal) glucose residue, while α-glucosidase II, a heterodimer composed of catalytic (α) and regulatory (β) subunits, removes the two innermost α1,3-linked glucose residues. This processing is essential for glycoprotein folding, maturation, and quality control, facilitating interaction with molecular chaperones such as calnexin and calreticulin. Both enzymes are validated drug targets for modulation of viral infectivity (by misfolding viral glycoproteins) and potentially other diseases involving secretory protein processing.

Other names

α-glucosidase I (also known as glucosidase I, GCSI, EC 3.2.1.106)α-glucosidase II (also known as glucosidase II, GCSII, EC 3.2.1.84)

Inhibitors block sequential glucose trimming steps required for proper glycoprotein folding, resulting in misfolded glycoproteins and reduced infectivity or cell viability