Studies on four components of wheat gliadins

Abstract

1. 1. Three gliadins of Wichita wheat variety and one of Cappelle, with low electrophoretic mobility at acid pH, have been isolated for the first time and their amino acid compositions determined. 2. 2. The molecular weights were 73 000 and 74 000 for two of the Wichita proteins. 3. 3. Very high contents of glutamine, proline and to a lesser extent phenylalanine, occurred in all four, but cyst(e)ine and methionine were absent. 4. 4. Fingerprinting suggested close resemblances among the primary structures of the proteins particularly of the two possessing equal mobilities even though these came from widely differing varieties. Nevertheless amino acid analysis indicated that some structural differences were present among these two proteins. 5. 5. There is evidence that these components may exhibit microheterogeneity and consist of several very closely related species, probably differing slightly in the degree of amidation. 6. 6. The results in this paper and of other recent work suggest that the gliadins have such overall similarities in amino acid composition that they have arisen from a single precursor by mutation.