Arginine from clupein

Nakahara, C., Iwai, K., Ando, T. Fractionation of arginine-containing peptides obtained from clupeine Z component (in Japanese). Seikagaku (J. Japan. Biochem. Soc.) 39, 463—472 (1967). 

Protamines. Strongly basic proteins of low molecular weight (4,000 to 8,000). They are rich in arginine. Examples are clupein from herring and scombrin from mackerel. 

Since two-thirds of the residues in clupein are arginine it follows that the sequence Arg.Arg must occur frequently in the molecule, and the dipeptide has often been isolated. Felix and Schuberth (1942) have described a method for the preparation of Arg.Arg and obtained 12.5 g. of the pure diflavianate from 50 g. clupein. 

Before 1960, all structural studies of protamines had been performed with wholly unfractionated or only partially fractionated specimens. The C-terminal residues of most of the protamines studied were occupied exclusively by arginine and the N-terminal residues mainly by proline, while the evidence for the presence of both proline and alanine in whole clupeine obtained from Pacific herring [Ando et al. 1955, 1957 (1, 2), 1958 (2)], indicated the presence of more than two molecular species in clupeine. 

As can be seen from Table VIII-3, satisfactory amounts (approximately 85 to 100 %) of peptides were recovered these included the sequences of all the monoamino-acids present among the arginine residues in clupeine Z. This indicates that each such sequence occurs once in a molecule. The following partial structure was given for clupeine Z ... 

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