Commercially available fig latex contains several endo-β-N-acetylglucosaminidases which catalyze the reaction: (Man)nG1cNAcβ1→4G1cNAcAsn → (Man)nG1cNAc + G1cNAcAsn. Using (NH4)2SO4 fractionation followed by chromatography on Sephadex G-100 and DEAE-Sephadex A-50, two distinct types of endo-β-N-acetylglucosaminidases have been partially purified and characterized. One, called F-I, hydrolyzes the di-N-acetylchitobiosyl linkage in the glycopeptide, (Man)3(G1cNAc)2Asn prepared from human IgG, much faster than that linkage in the glycopeptides, (Man)5(G1cNAc)2Asn and (Man)6(G1cNAc)2Asn both from ovalbumin. The other, called F-II, hydrolyzes the same linkage in (Man)5(G1cNAc)2-Asn and (Man)6(G1cNAc)2Asn, but not that in (Man)3(G1cNAc)2Asn.
Biochemical and Biophysical Research Communications 76(2), pp.317-323