Structural characterization of a novel glycoprotein in wheat germ and its physicochemical properties.

Wheat germ is well known for as a rich source of nutrients. In this study, a novel water soluble wheat germ glycoprotein (WGPII), with an average molecular weight of 14.5 kDa, was extracted from commercial wheat germ. The protein segments occupy 70.38% (w/w) of WGPII, and are rich in glutamic acid. The sugar residues of WGPII are primarily composed of (1 → 5)-linked α-l-Araf, (1 → 3, 6)-linked-α-d-Manp, (1→)-α-d-Glcp, (1 → 6)-linked-α-d-Glcp, (1 → 6)-linked-α-d-Galp, (1 → 4)-linked-α-d-Xylp and (1 → 4,6)-linked-α-d-Glcp. The protein and polysaccharide parts are linked by O-linkage bonds. WGPII is highly stable in aqueous solution at low concentrations (0.1-1 mg/mL), and show high thermo stability.