N-glycoprotein deglycosylase （peptide∶N-glycanase, abbreviated PNGase）, widely distributed in prokaryotes and eukaryotes, hydrolyzes asparagine （Asn）-linked oligosaccharides on polypeptides and releases intact oligosaccharide chains. Prokaryotic PNGases are found only in Elisabethella meningitidis septica, and there are two PNGases in total, named PNGase F and PNGase F-II. PNGase F-II, while having the function of PNGase F, hydrolyzes and releases intact glycan chains containing α-1,3-core fucoidan glycosylated N-glycoproteins of plant and insect origin, and functions in the same way as PNGase A.