ò-Mannosidase (}, mannanase, mannase, ò-<small>D</small>-mannosidase, ò-mannoside mannohydrolase, exo-ò-<small>D</small>-mannanase, lysosomal ò A mannosidase) is an enzyme with systematic name ò-<small>D</small>-mannoside mannohydrolase, which is in humans encoded by the MANBA gene. This enzyme catalyses the following chemical reaction
This gene encodes a member of the glycosyl hydrolase 2 family. The encoded protein localizes to the lysosome where it is the final exoglycosidase in the pathway for N-linked glycoprotein oligosaccharide catabolism. Mutations in this gene are associated with ò-mannosidosis, a lysosomal storage disease that has a wide spectrum of neurological involvement.