Purification and characterization of seed globulins from Brassica juncea, B. nigra, and B. hirta

Two globulins have been isolated from seeds of Brassica juncea, Brassica nigra, and Brassica hirta and the homogeneity of the preparations has been established by polyacrylamide gel electrophoresis and analytical ultracentrifugation. The respective proteins from the various species have similar physical properties but differ significantly in chemical composition. The relationship between the amino acid compositions of the proteins from seeds of the above species and also Brassica campestris is examined; the suggestion of hybridization of Brassica campestris and Brassica nigra to produce Brassica juncea is supported.