Isolation and Characterization of Glucosamine-containing Storage Glycoproteins from the Cotyledons of Phaseolus aureus.

Cotyledons of Phaseolus aureus contain protein-bound glucosamine which is metabolized during germination. The glucosamine is present in storage glycoproteins, and these are concurrently metabolized along with the glucosamine. These glycoproteins are associated with protein bodies. Characterization of the glucosamine-containing storage proteins showed them to be identical with vicilin and legumin, the major storage proteins of the Leguminosae. Phaseolus aureus vicilin has a sedimentation constant of 8.0S and is made up of four nonidentical subunits. It contains 0.2% glucosamine and 1% mannose. Legumin has a sedimentation constant of 11.3S and is made up of three nonidentical subunits. It contains about 0.1% glucosamine.