PRIMARY STRUCTURE OF 2S ALBUMIN FROM SEEDS OF LUPINUS-COSENTINII

The 2S albumin from seeds of Lupinus cosentinii Guss. was purified, an d the complete amino acid sequences of the dominating small and large subunit were determined by automated Edman degradation of the reduced and SE pyridylethylated polypeptides and of their enzymatic fragments. The small subunit of the 2S albumin consists of 35 amino acid residue s resulting in a molecular mass (M-r) of 4233. The large subunit conta ins 73 amino acid residues (M-r = 8627). The two polypeptide chains ar e linked by two interchain disulphide bonds. In addition, the large po lypeptide contains two intrachain disulphide bridges and one free sulp hydryl group. A high degree of homology (88-89%) exists between the pr imary structure of Me 2S albumin from L. cosentinii and those from oth er Lupinus species. The positions of the cysteines and of some other a mino acids are conserved not only in most of the Dicotyledoneae 2S alb umins sequenced so far but also in other storage proteins.