The correction of Hunter fibroblasts by exogenous iduronate sulfate sulfatase: biochemical and ultrastructural studies.

The exogenous addition of iduronate sulfate sulfatase to cultured fibroblasts of Hunter patients resulted in a full correction of the metabolic defect as demonstrated by chemical and ultrastructural analyses. As little as 25% of the normal fibroblasts' enzyme levels were sufficient for this correction. The half-disappearance time of the internalized enzyme was 3-4 days. Prolonged incubation of corrected cells resulted in a gradual reaccumulation of mucopolysaccharides.