Identification of an intermediate form of beta-N-acetylhexosaminidase in chorionic villi

A minor form of beta-N-acetylhexosaminidase has been found in chorionic villi, in addition to the major forms A and B. This form does not hydrolyze the 4-methylumbelliferyl-2-acetamido-2-deoxy-beta-D-glucopyranoside-6-sulpha te substrate, is thermostable, has a higher mol mass (120,000) than A and B (100,000) and on analytical isoelectric focusing, it shows a microheterogeneity with values ranging between 6.3 and 7.0. For these characteristics, it resembles beta-N-Acetylhexosaminidase P from pregnancy serum, from which is chromatographically indistinguishable.