TY - JOUR
T1 - Identification of tyrosine sulfation in Conus pennaceus conotoxins α-PnIA and α-PnIB
T2 - Further investigation of labile sulfo- and phosphopeptides by electrospray, matrix-assisted laser desorption/ionization (MALDI) and atmospheric pressure MALDI mass spectrometry
AU - Wolfender, Jean Luc
AU - Chu, Feixia
AU - Ball, Haydn
AU - Wolfender, Florence
AU - Fainzilber, Michael
AU - Baldwin, Michael A.
AU - Burlingame, Alma L.
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1999
Y1 - 1999
N2 - Liquid chromatography/electrospray ionization mass spectrometry was used to investigate the peptide composition of the venom of Conus pennaceus, a molluscivorous cone shell from the Red Sea. Based on observed M(r)S, this venom contained all known conotoxins previously isolated and identified from this species. Interestingly, the doubly protonated species of only two of these conotoxins, α-PnIA and α-PnIB, showed additional related ions at +40 m/z (+80 Da), indicating the presence of either sulfation or phosphorylation in both components. High-performance liquid chromatographic (HPLC) fractions containing these two conotoxins were examined by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry in both positive and negative ion modes, as well as by MALDI high-energy collision-induced dissociation. These experiments established the presence of a single sulfated tyrosine residue within both α-PnIA and α-PnIB. Hence their post-translationally modified sequences are GCCSLPPCAANNPDY(S)C-NH2 (α-PnIA) and GCCSLPPCALSNPDY(S)C-NH2 (α-PnIB). This assignment was supported by comparison of their mass spectral behavior with that of known sulfated and phosphorylated peptides. This data clarified further the distinguishing features of the ionization and fragmentation of such modified peptides. Selective disulfide folding of synthetic α-PnIB demonstrated that both sulfated and non-sulfated toxins co-elute on reversed-phase HPLC and that α-PnIB possesses the same disulfide connectivity as other 'classical' α-conotoxins reported previously.
AB - Liquid chromatography/electrospray ionization mass spectrometry was used to investigate the peptide composition of the venom of Conus pennaceus, a molluscivorous cone shell from the Red Sea. Based on observed M(r)S, this venom contained all known conotoxins previously isolated and identified from this species. Interestingly, the doubly protonated species of only two of these conotoxins, α-PnIA and α-PnIB, showed additional related ions at +40 m/z (+80 Da), indicating the presence of either sulfation or phosphorylation in both components. High-performance liquid chromatographic (HPLC) fractions containing these two conotoxins were examined by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry in both positive and negative ion modes, as well as by MALDI high-energy collision-induced dissociation. These experiments established the presence of a single sulfated tyrosine residue within both α-PnIA and α-PnIB. Hence their post-translationally modified sequences are GCCSLPPCAANNPDY(S)C-NH2 (α-PnIA) and GCCSLPPCALSNPDY(S)C-NH2 (α-PnIB). This assignment was supported by comparison of their mass spectral behavior with that of known sulfated and phosphorylated peptides. This data clarified further the distinguishing features of the ionization and fragmentation of such modified peptides. Selective disulfide folding of synthetic α-PnIB demonstrated that both sulfated and non-sulfated toxins co-elute on reversed-phase HPLC and that α-PnIB possesses the same disulfide connectivity as other 'classical' α-conotoxins reported previously.
KW - Atmospheric pressure matrix-assisted laser desorption/ionization
KW - Conotoxin
KW - Electrospray ionization
KW - Matrix-assisted laser desorption/ionization
KW - Sulfotyrosine
UR - http://www.scopus.com/inward/record.url?scp=0032964781&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032964781&partnerID=8YFLogxK
U2 - 10.1002/(SICI)1096-9888(199904)34:4<447::AID-JMS801>3.0.CO;2-1
DO - 10.1002/(SICI)1096-9888(199904)34:4<447::AID-JMS801>3.0.CO;2-1
M3 - Article
C2 - 10226369
AN - SCOPUS:0032964781
SN - 1076-5174
VL - 34
SP - 447
EP - 454
JO - Journal of Mass Spectrometry
JF - Journal of Mass Spectrometry
IS - 4
ER -