β‐Mannosidase in human leukocytes and fibroblasts

Abstract
In human leukocytes and fibroblasts β-mannosidase activity has a unimodal pH optimum (4.0–4.5). Markedly reduced activity is found in I-cell disease. Normal activities in human fibroblasts are ten times higher than in the goat, in which species a deficiency disease has been described.