Abstract
The amino acid sequences of the three bradykinin-potentiating peptides from the venom of Agkistrodon halys blomhoffii (potentiators B, C, and E), which had been previously presented by Kato and Suzuki using conventional stepwise techniques, were smoothly confirmed by means of mass spectrometry coupled with enzymatic cleavage techniques. In the course of the sequencing, it was suggested that the preparation of potentiator B previously purified is contaminated by a small amount of the peptides with analogous amino acid sequences. The results showed the usefulness of mass spectrometric method in the sequence determination of naturally occurring peptides having N-terminal pyroglutamic acid and abundant proline residues. Mass spectrometric method was also effective for the detection of a small amount of contaminating peptide in the sample.
