Processing enzyme glucosidase II: proposed catalytic residues and developmental regulation during the ontogeny of the mouse mammary gland.

Following the action of glucosidase I to clip the terminal alpha1,2-linked glucose, glucosidase II sequentially cleaves the two inner alpha1,3-linked glucose residues from the Glcalpha1,2Glcalpha1,3Glcalpha1,3Man(9)GlcNAc(2) oligosaccharide of the incipient glycoprotein as it undergoes folding and maturation. Glucosidase II belongs to family 31 glycosidases. These enzymes act by the acid-base catalytic mechanism.

Synthesis of a novel photoaffinity derivative of 1-deoxynojirimycin for active site-directed labeling of glucosidase I.

Glucosidase I releases the distal alpha1,2-glucosyl residue in the Glc(3)Man(9)GlcNAc(2) precursor immediately after its transfer from the dolichol-P-P-linked intermediate in the endoplasmic reticulum and triggers the processes for the posttranslational remodeling, folding, and maturation of N-linked glycoproteins. The enzyme has been purified and characterized from several eukaryotic systems. Its cDNA and the gene have also been cloned.