Mannosidosis: Deficiency of a specific α-mannosidase component in cultured fibroblasts

Evidence is presented which shows that the enzymatic defect in mannosidosis, the deficiency of α-mannosidase, is expressed in cultured skin fibroblasts from patients with mannosidosis. Additionally, by Cellogel electrophoresis, the enzyme can be separated into two major components (a heat stable component missing in mannosidosis fibroblasts with a pH optimum of 3.6-4.0 and a heat labile component present in mannosidosis fibroblasts with a pH optimum of 5.6-6.0). The specific activity and electrophoresis of α-mannosidase from cultured amniotic fluid cells are also shown to be similar to cultured skin fibroblasts.