ISOLATION AND CHARACTERIZATION OF A 20 KD PROLAMIN FROM KODO MILLET (PASPALUM-SCROBICULATUM) (L.) - HOMOLOGY WITH OTHER MILLETS AND CEREALS

The homologus 20 kD prolamin from kodo millet and other minor millets viz. barnyard, little and foxtail millets, were purified using prepara tive gel electrophoresis and reversed phase high performance liquid ch romatography (RP-HPLC). The amino acid composition of the purified 20 kD prolamin protein from different minor millets revealed higher conte nt of glutamic acid, alanine, leucine and serine and lower quantity of lysine and methionine. They contain 55 to 58 percent of nan-polar ami no acids which make them more hydrophobic than other protein fractions . The total number of amino acid residues per polypeptide chain ranged from 152 to 155 based on theoretical calculation. Peptide mapping of the 20 kD prolamin hydrolyzed with trypsin gave fewer cleavage product s than expected. The antigenic relationships among these minor millets and cereals viz. wheat, maize, rice, sorghum, finger millet and pearl millet were studied using the antibody raised against the 20 kD prola min. Cross reactivity was seen in all the minor millets at the 20 kD r egion. But in barnyard and little millets lower molecular weight polyp eptides also cross reacted with the antibody. Immunoblotting studies r evealed that the prolamins from other cereals and millets are related to the 20 kD prolamin of kodo millet. Rice was the only common cereal that did not cross react immunologically with the antibody raised agai nst 20 kD prolamin of kodo millet.