Assay for cerebroside sulfate (sulfatide) sulfatase in cultured skin fibroblasts with the natural activator protein.

A simple procedure was developed to assay the ability of arylsulfatase A in extracts of cultured skin fibroblasts to degrade the natural substrate, sulfatide, in the presence of the physiological activator protein but without detergents. Inhibitory substances were removed by dialysis and by batch-wise ion-exchange chromatography. The enzyme recoveries during purification were monitored with a newly developed method that employs the chromogenic substrate 4-nitrocatecholsulfate at an incubation temperature of 4 degrees C. The residual sulfatidase activities determined with this procedure in fibroblasts from patients with various forms of MLD correlated well with the severity of the disease.