Nature of SfGlcNAcase-1 and -3 membrane association. Microsomal fractions containing 40 ug of total protein from Sf9 cells infected with (B) wild type baculovirus, (C) AcGlcNAcase-1, or (D) AcGlcNAcase-3 were subjected to two rounds of dilution, sonication, and centrifugation, as described in Materials and Methods. The microsomal pellets were then solubilized, incubated for about 16 h with GnGn, and the reaction products were recovered and analyzed by reverse-phase HPLC, as described in Materials and Methods. (A) Elution of untreated synthetic oligosaccharides and their structures, as in Figure 4.