Endo F3 cleaves free or Asparagine-linked triantennary or biantennary oligosaccharides,as well as triamnnosyl chitobiose core structures. It cleaves between the two N-acetylglucosamine residues in the diacetylchitobiose core of the oligosaccharide, generating a truncated sugar molecule with one N-acetylglucosamineresidue remaining on the asparagine. In contrast, PNGase F removes the oligosaccharide intact. Alpha 1-3 fucosylation will inhibit enzymatc activity.