Characterization of Oilgosaccharide Moieties of Rat Intestinal Phytase

Abstract

Phytase of rat intestine had a large amount of oilgosacchanrides ; The enzyme consisted of two different subunits with the molecular weights of 90 KDa and 70 KDa in its intack 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 70KDa subunit contains only the N-linked oilgosaccharide chains, while the 90KDa subunit ocntains O-linked oilgosaccharides as well as N-linked ones. Enzyme-linked lectin assays suggeted that bisecting N-acetyl-D-glucosamine and galactose 1-4 N-acetyl-D-glucosamine structures were present and that fucose was included in these oilgosaccharide moieties. Sialic acid was not found in either subunit.

Keywords

• Phytase;
• Rat intestine;
• Enzyme-linked Lectin assay