Necessary for the catabolism of N-linked carbohydrates released during glycoprotein turnover. Cleaves all known types of alpha-mannosidic linkages. Defects in MAN2B1 are the cause of lysosomal alpha- mannosidosis (AM). AM is a lysosomal storage disease characterized by accumulation of unbranched oligosaccharide chains. This accumulation is expressed histologically as cytoplasmic vacuolation predominantly in the CNS and parenchymatous organs. Depending on the clinical findings at the age of onset, a severe infantile (type I) and a mild juvenile (type II) form of alpha-mannosidosis are recognized. There is considerable variation in the clinical expression with mental retardation, recurrent infections, impaired hearing and Hurler- like skeletal changes being the most consistent abnormalities. Belongs to the glycosyl hydrolase 38 family. Note: This description may include information from UniProtKB.
Protein type: EC 188.8.131.52; Glycan Metabolism - other glycan degradation; Hydrolase