Intermediate forms of human β-N-acetylhexosaminidase lack activity towards 4-methylumbelliferyl β-N-acetylglucosaminide 6-sulphate

Abstract

4-Methylumbelliferyl β-N-acetylglucosaminide 6-sulphate was purified from a mixture containing its unsulphated precursor. The subtrate was used to test for the presence of functional α-subunits in 'intermediate' forms of human β-N-acetylhexosaminidase in samples of normal and pregnancy serum and in extracts of placenta and lymphocytes from a patient with common acute lymphoblastic leukaemia. Intermediate forms in these samples had no activity towards 4-methylumbelliferyl β-N-acetylglucosaminide 6-sulphate, indicating that they lack α-subunits.