Galactokinases, which catalyze the phosphorylation of galactose and possibly other monosaccharides, can provide an activated sugar donor to synthesize sugar-containing molecules. In this study, a novel galactokinase from human gut symbiont Akkermansia muciniphila ATCC BAA-835 (GalKAmu) was expressed and characterized. GalKAmu displayed broad substrate tolerance, with catalytic activity towards Gal (100%), GalN (100%), GalA (20.2%), Glc (52.5%), GlcNAc (15.5%), Xyl (<5%), ManNAc (58%), ManF (37.4%) and L-Glc (80%). Most interestingly, this was the first GalK isoform which can tolerate ManNAc. Thus, our characterization of GalKAmu broadens the substrate selection of galactokinases.
Galactokinases, which catalyze the phosphorylation of galactose and possibly other monosaccharides, can provide an activated sugar donor to synthesize sugar-containing molecules. In this study, a novel galactokinase from human gut symbiont Akkermansia muciniphila ATCC BAA-835 (GalKAmu) was expressed and characterized. GalKAmu displayed broad substrate tolerance, with catalytic activity towards Gal (100%), GalN (100%), GalA (20.2%), Glc (52.5%), GlcNAc (15.5%), Xyl (<5%), ManNAc (58%), ManF (37.4%) and L-Glc (80%). Most interestingly, this was the first GalK isoform which can tolerate ManNAc. Thus, our characterization of GalKAmu broadens the substrate selection of galactokinases.