Molecular masses and primary structure determination of Conus peptides
, such as alpha-, mu- and omega-conotoxins, conantokins and conopressi
ns, were accurately measured by state-of-the-art mass spectrometric te
chniques using only 1-2 pmole quantities. Soft ionization of Conus pep
tides under electrospray, matrix-assisted laser desorption and continu
ous flow frit-FAB conditions produced their corresponding singly and m
ultiply charged molecular ions which can be detected by mass spectrome
tric analysis. The molecular masses of Conus peptides were obtained by
the deconvolution of the multiply charged pseudo-molecular ions. Mixt
ure analysis without chromatographic separation can be accomplished by
this approach. The ions formed during collision-induced dissociation
of either singly or multiply charged ions of any reduced and derivatiz
ed peptide provided the corresponding sequences of the amino acids. Pr
eliminary investigations indicate that the developed techniques and pr
ocedures could be applied in order to characterize the peptides presen
t in unknown Conus venoms from the Bay of Bengal region.