title: beta-N-acetyl-D-glucosaminidase isoenzymes from human amnionic membranes.
abstract: Two beta-N-acetylglucosaminidase isoenzymes (A and B) have been identified and purified from amnionic fetal membrane. The final specific activity of A and B isoenzymes increased 225- and 185-fold respectively by a purification scheme, which included a lyophilized extract, chromatofocusing on PBE 94, pH range 5.5 to 4.0, and affinity chromatography on p-aminophenyl-2-acetamido-2-deoxy-1-thio-beta-D-glucopyranoside covalently linked to Sepharose-4B. Different electrophoretic mobility, thermostability and different thiol group modifications of the two isoenzymes were found. Acetate was a more effective competitive inhibitor than were iodoacetamide, N-acetylglucosamine and N-acetylgalactosamine more than glucosamine and galactosamine, confirming a specific 'acetamido receptor site' for both the isoenzymes.
mesh_terms: D000118:Acetylglucosaminidase / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D000650:Amnion / Q000201:enzymology*; D006596:Hexosaminidases / Q000302:isolation & purification*; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006902:Hydroxymercuribenzoates / Q000494:pharmacology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D013849:Thimerosal / Q000494:pharmacology
chemical_list: D006902:Hydroxymercuribenzoates; D007527:Isoenzymes; D008670:Metals; C030601:4-hydroxymercuribenzoate; D013849:Thimerosal; D006596:Hexosaminidases; D000118:Acetylglucosaminidase