Structural characteristics of a major seed albumin of Pisum sativum

The major pea seed albumin from Pisum sativum was carboxymethylated, cleaved with CNBr, and submitted to sequence analysis of the fragments in order to characterize the structural organization of the protein chains. Four major pools of largely homogeneous CNBr fragments were obtained, and likely N- and C-terminal fragments were identified. Structural analysis suggested the presence of single positions with microheterogeneities. It also revealed structures with long segments of distinct homology (52% structural identity), indicating the presence of different but related protein chains, or less likely, of repetitive structural elements within a chain. However, preparations appear largely homogeneous in protein class, and contain similar polypeptide chains of about 200 residues in mainly hydrophilic structures, with few methionine and cysteine/half-cystine residues.