The Complete Amino Acid Sequences of Both Subunits of the Sweet Protein Monellin

The amino acid sequences of both chains of the sweet protein Monellin have been determined. Since chain separation could not be accomplished easily, cyanogen bromide cleavage at the only methionine residue (in the B-chain) was performed and the three products obtained after cyanogen bromide cleavage were separated. For the identification of amino acid phenylthiohydantoins, high performance liquid chromatography was employed. Thus 37 out of a total of 44 residues of the A chain and 40 out of a total of 42 residues of the large CNBr fragment of the B chain could be determined after Edman degradation of the polypeptides on an automated sequenator.