Endo-β-N-acetylglucosaminidase (ENGase) belonging to the glycoside hydrolase family 85 (GH85) is a series of dual-functional enzymes that not only hydrolyze the glycosidic bonds of the N,N′-diacetylchitobiose moieties of N-glycan cores but also transfer chemically synthesized-homogeneous glycans onto glycoproteins. This unique transglycosylation activity enables them to modify proteins with a defined N-glycan structure. In this study, we identified ENGase homolog in Trypanosoma brucei genome by database search. The gene encoding ENGase was cloned into an expression vector with an N-terminal Nus tag, and expressed in Escherichia coli cells. The recombinant ENGase (Nus-Endo Tb) exhibited hydrolytic activity for high-mannose, bi-antennary N-linked oligosaccharides. Such hydrolytic activity can be applied to hydrolyze N-glycans attached to RNase B and human transferrin. Moreover, Nus-Endo Tb also can transfer a sialobiantennary type complex oligosaccharide onto MU-GlcNA, which indicated its transglycosylation activity.
CUI Juan et al
. Expression, purification and characterization of a novel Endo-β-N-acetylglucosaminidase from Trypanosoma brucei[J]. Food and Fermentation Industries, 2018
, 44(8)
: 8
-13
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DOI: 10.13995/j.cnki.11-1802/ts.016879