O-GlcNAcase (OGA) is an enzyme responsible for the hydrolysis of glycosidic bonds in O-GlcNA acylated proteins. It exhibits its enzymatic activity in vitro by efficiently utilizing substrates such as p-nitrophenyl-β-GlcNAc and 4-methylumbelliferone-GlcNAc. O-GlcNAcase/OGA Protein, B. thetaiotaomicron (His) is the recombinant O-GlcNAcase/OGA protein, expressed by E. coli , with N-6*His labeled tag.