Properties of α-l-iduronidase in cultured skin fibroblasts from α-l-iduronidase-deficient patients

On DEAE cellulose column chromatography, α-l-iduronidase in cultured skin fibroblasts was resolved into two distinct components, forms A and B. They had similar Km values for 4-methylumbelliferyl-α-l-iduronide, but differed in pH optima and thermal stability. Form B was more heat-stable than form A.