Isolation of a glycopeptide from a 7S protein in soybean globulins

Abstract Further evidence for the glycoprotein nature of a 7S protein in soybean globulins was demonstrated by isolation of a glycopeptide from proteolytic digest. The homogeneity of the isolated glycopeptide was ascertained by amino-terminal analysis and high-voltage electrophoresis. This glycopeptide had a molecular weight of about 9870 and was composed of 17 amino acid residues (Asp6, Thr3, Gly3, Ala3, Glu1, Ser1) and 51 sugar residues (mannose39, glucosamine12). Considering that the content of carbohydrate moiety in this glycopeptide corresponds to that in the original protein, it may be concluded that the carbohydrate moiety is present in the protein as a single polysacchavide unit.