Peptide-N4-( N-acetyl-β-glucosaminyl) asparagine amidases [PNGases (peptide N-glycosidases), N-glycanases, EC 3.5.1.52] are essential tools in the release of N-glycans from glycoproteins. We hereby report the discovery and characterization of a novel bacterial N-glycanase from Terriglobus roseus with an extremely low pH optimum of 2.6, and annotated it therefore as PNGase H +. The gene of PNGase H + was cloned and the recombinant protein was successfully expressed in Escherichia coli. The recombinant PNGase H + could liberate high mannose-, hybrid- and complex-type N-glycans including core α1,3-fucosylated oligosaccharides from both glycoproteins and glycopeptides. In addition, PNGase H + exhibited better release efficiency over N-glycans without core α1,3-fucose compared with PNGase A. The facile expression, non-glycosylated nature, unusual pH optimum and broad substrate specificity of this novel type of N-glycanase makes recombinant PNGase H + a versatile tool in N-glycan analysis.
PNGase H +, from T. roseus was successfully cloned and expressed in E. coli. It shows activity in extremely acidic conditions and can release all types of N-glycans including core α1,3-fucosylated N-glycans from glycoproteins and glycopeptides in high efficiency.