No allergens from this plant have yet been characterised.
A number of proteins have been isolated and described as occurring in Japanese millet. The allergenic potential of these proteins was, however, not evaluated.
Barnyard millet, Common millet, Little millet, Foxtail millet, and Kodo millet were studied. The protein contents of the selected decorticated Millets were found to be 11.0, 12.3, 12.9, 10.5 and 10.6% respectively. Prolamin is a major storage protein in Foxtail millet, whereas glutelin is a major storage protein in all the other Millets. A protein band at the molecular weight range of 20 kDa was found to be homologous in all except Proso millet (2).
A Foxtail millet glutelin of 60 kDa (MG60) has been isolated. The primary structure at the N-terminal end was almost identical to that of the granule-bound starch synthase (GBSS) proteins from Rice, Barley, Maize, Wheat and Potato. Common epitopes from these starch-storing cereals were corroborated by immunoblot analysis, strongly suggesting a close relationship (3).
In a study, the antigenic relationships among "minor Millets" (Barnyard, Little and Foxtail millets) and other cereals (Wheat, Maize, Rice, Sorghum, Finger millet and Pearl millet) were evaluated using an antibody raised against a 20 kDa prolamin from Kodo millet. It was demonstrated that the prolamin was related to the prolamins from the other plants. Rice was the only common cereal that did not cross-react immunologically with the 20 kDa prolamin of Kodo millet (4).
A subtilisin inhibitor has been isolated from seeds of Foxtail millet. (5)
Proteinase inhibitors (trypsin/chymotrypsin) have been demonstrated to be present in Finger millet, Sorghum, Pearl millet, Foxtail millet, and Japanese millet (6). The amino acid sequence of an isolated trypsin inhibitor (7) had a high degree of homology to Bowman-Birk type inhibitors from leguminous and gramineous plants (8).
Cross-allergenicity among Rice, Wheat, Maize, Japanese millet and Foxtail millet was examined by IgE antibody determination and RAST inhibition studies, and significant close correlations among the 5 cereal grain extracts were demonstrated. A Rice protein of 16 KDa was shown to be one of the major allergens in Rice grain extracts (9-10). The protein showed sequence homology to Wheat alpha-amylase inhibitor and Barley trypsin inhibitor (11). The clinical relevance of this protein was not assessed.