Separation of the β-Aspartamido-carbohydrate Fractions from Soybean 7S Protein: Protein-Carbohydrate Linkage

Abstract

Using a Dowex 50-X2 column and eluting with a 1mM sodium acetate buffer (pH 2.6), three L-β-aspartamido-carbohydrate (Asn-carbohydrate) fractions have been isolated in 19% yield from the pronase digest of a 7S soybean protein. The Asn-carbohydrates were composed of one asparagine, two glucosamine and seven, eight and nine mannose residues. Further, 1-L-β-aspartamido-2-acetamido-1, 2-dideoxy-β-D-glucose (Asn-GlcNAc), which is derived from the protein-carbohydrate linkage, was produced by partial hydrolysis of the Asn-carbohydrates.