Variations in the Methionine-rich Protein Composition of the Genus Arachis¹

Methionine-rich proteins (MRP) from seeds of different species of the Genus Arachis were isolated and analyzed by gel electrophoresis to detect possible compositional differences. One-dimensional gel electrophoretic analysis showed presence of quantitative and qualitative variations among the MRP-fractions. Following two-dimensional gel electrophoresis, the MRP-fractions were found to contain three groups of polypeptides with apparent molecular weights of approximately 21,000; 19,000 and 16,000, and isoelectric points between 5.1 and 5.8. Within each molecular weight group the number of polypeptides varied between 1 and 3.