Separation of Component-Polypeptides of Glutenin by Isoelectric Focusing

1. By isoelectric focusing S-cyanoethyl glutenin was observed to be composed of various component-polypeptides having a pI spectrum in a pH range from 6 to 9.

2. During isoelectric focusing a precipitation zone was built up in the column in spite of the presence of 6 m urea. The amount of the precipitate formed was less with S-cyanoethyl glutenin than with S-sulfo glutenin.

3. S-Cyanoethyl glutenin was divided into eight fractions by isoelectric focusing. By starch-gel electrophoresis it was suggested that Fractions I, III and P were mainly composed of a single component.

4. Major N-terminal amino acids of Fractions I, III and P were phenylalanine, glycine and alanine, respectively. In the amino acid composition, distinct differences were observed in the respective fractions, especially in Fraction P. Fraction P showed a much higher content of basic amino acids and a lower content of glutamic acid in comparison with the other two.