β-Mannosidase participates in cleaving the β(1–4)-linked mannose located at the nonreducing end of N-glycosylated proteins. It is involved in the polysaccharide degradation pathway. In humans, mutations in the gene are associated with β-mannosidosis, a lysosomal storage disease. Low levels of β-Mannosidase due to mutations also lead to nystagmus, an eye disorder associated with involuntary eye movements.
