European Journal of Biochemistry 1992-06-15

C-terminal sequencing of protein. A novel partial acid hydrolysis and analysis by mass spectrometry.

A Tsugita, K Takamoto, M Kamo, H Iwadate

Index: Eur. J. Biochem. 206(3) , 691-6, (1992)

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Abstract

Peptides or proteins were hydrolyzed by vapors of 90% pentafluoropropionic acid or heptafluorobutyric acid at 90 degrees C for various time periods. The hydrolyzate mixtures analyzed by both fast-atom-bombardment and electrospray ionization mass spectrometry showed a series of C-terminal successive degradation molecular ions. The degradation reaction may be due to the selective formation of an oxazolone ring at the C-terminal amino acid, followed by hydrolytic removal of the C-terminal amino acid. The major side reactions were cleavages of the peptide bonds at the C side of the internal aspartic acid residue and the N side of serine residue.