We have obtained several amino acid sequences from purified polypeptides of a wheat endosperm storage globulin previously described as 'triplet' protein. The amino acid sequence data supported by immunochemical analysis using anti-oat 12S globulin antibodies, provide definitive evidence that the triplet protein is homologous to pea legumin and related seed storage proteins of oats, rice and several dicotyledonous species. Thus, it is now proposed that the triplet protein of wheat be renamed 'triticin'. The oat globulin antibodies also cross-reacted strongly with the high-molecular-weight (HMW) glutenin subunits which have been implicated in bread-making quality.