Abstract
Two constituent polypeptide chains of castor bean hemagglutinin (CBH-A) were isolated from the performic acid-oxidized or reduced-carboxymethylated CBH-A by chromatography on DEAE-cellulose or Sepharose 4B. From the analyses of the N-terminal amino acids, the amino acid compositions and the tryptic peptides of each chain, it was found that the larger chain with mol. wt. 34,000 and the smaller chain with mol. wt. 31,000 were homologous with the Ala and He chains of ricin D, respectively, and the subunit structure of CBH-A is represented as (α′/β′)2 in relation to αβ of ricin D.