Multiple isoelectric and recognition forms of human β-glucuronidase activity

Abstract

Human β-glucuronidase activity can be separated into multiple forms by isoelectric focusing in urea. Liver, placenta, fibroblasts, and blood platelets show different distributions of activity in the pI 5.0–7.5 range. Enzyme from platelets, placenta, or liver, which is recognized and taken up by deficient fibroblasts in culture, falls mainly in the pI 6.0–6.5 range. Even these fractions, which exhibit high uptake, are heterogeneous. When high-uptake material (pI 6.0–6.5) is added to deficient cells in culture, it is taken up and converted to low-uptake material intracellularly.