Maselli Vita M, Brinkworth Craig S, Bowie John H, Tyler Michael J
Department of Chemistry, The University of Adelaide, South Australia, 5005.
Rapid Commun Mass Spectrom. 2004;18(18):2155-61. doi: 10.1002/rcm.1602.
The amino acid sequences of seven signiferin peptides are provided by consideration of tandem mass spectrometric (MS/MS) data for the respective MH+ and [M--H]- precursor ions. These methods do not differentiate between isomeric residues Leu and Ile; these were identified using the Edman degradation technique. The sequence of signiferin 1, a new smooth muscle contracting neuropeptide (RLCIPYIIPC-OH) containing a disulfide bridge, is best determined using the collision-induced dissociation (CID) spectrum of the [M--H]- anion. The initial fragmentation of this system involves loss of H2S2, which furnishes an open-chain system that is readily sequenced using the alpha and beta backbone cleavage anions.
