A recognition marker required for uptake of a lysosomal enzyme by cultured fibroblasts

N-acetyl-β-hexosaminidase secreted by cultured skin fibroblasts from normal individuals, or from patients with mucopolysaccharidoses, is effectively captured by fibroblasts derived from patients with Sandhoff disease. On the other hand, N-acetyl-β-hexosaminidase from several other sources (including placenta, urine, and secretions of fibroblasts from patients with mucolipidosis II or III) is taken up to a much lesser extent. The uptake of the normal fibroblast hydrolase can be abolished by periodate oxidation under conditions that do not affect its catalytic activity, stability, or binding to Concanavalin A - Sepharose. These results suggest that uptake into fibroblasts requires a specific marker on the enzyme.