A galactose-rich, cell-wall glycoprotein from styles of Nicotiana alata

Abstract

A basic, galactose-rich style glycoprotein (GaRSGP) encoded by a previously characterized style-specific cDNA (NaPRP4) has been isolated from the styles of Nicotian a alata and structurally characterized. The glycoprotein is associated with cell walls in the transmitting tract and is composed of approximately 25% (w/w) protein and 75% (w/w) carbohydrate. The purified glycoprotein appears as a smear of between 45-120 kDa on SDS-PAGE; the deglycosylated protein backbone has an apparent molecular weight of approximately 30 kDa. The glycoprotein is rich in the amino acids lysine, proline, and hydroxyproline and in the monosaccharides galactose and arabinose. it is one of only a few proline/hydro..