Characterization of oligosaccharide moieties of rat intestinal phytase

Phytase of Rat Intestine had a large amount of oligosaccharides; The enzyme consisted of two different subunits with the molecular weights of 90 KDa and 70 KDa in its intact form, whereas the apparent molecular weights tumed to 72 KDa and 52 KDa, respectively, after deglycosylation. The treatment with glycopeptidase F reduced the molecular weights from 90 KDa and 70 KDa to 83 KDa and 52 KDa, respectively, while endoglycosidase H caused no change in their molecular weights. These results indicate that the 70 KDa subunit contains only the N-linked oligosaccharide chains, while the 90 KDa subunit contains O-linked oligosaccharides as well as N-linked ones. Enzyme-linked lectin assays suggested that bisectingN-acetyl-D-glucosamine and galactose 1–4N-acetyl-D-glucosamine structures were present and that fucose was included in these oligosaccharide moieties. Sialic acid was not found in either subunit.