Precursor structure of omega-conotoxin GVIA determined from a cDNA clone.
The Ca2+ channel blocking neurotoxin, omega-conotoxin GVIA, is a 27-amino acid peptide with three disulfide bonds. We have determined the precursor structure of this peptide by analyzing a cDNA clone obtained from a Conus geographus venom duct library. The omega-conotoxin GVIA prepropeptide is 73 amino acids in length comprising a 22 amino acid signal sequence, an intervening region of 23 amino acids, and finally, a 27 amino acid toxin region. A C-terminal glycine residue is later processed to a C-terminal amide moiety. The omega-conotoxin GVIA precursor exhibits regions of strong homology to the previously characterized King-Kong peptide precursor, but shows surprising divergence as well. The possible significance of the precursor organization is discussed.
Colledge
C J
CJ
Department of Pathology, University of Utah, Salt Lake City 84112.
Hunsperger
J P
JP
Imperial
J S
JS
Hillyard
D R
DR
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry*; D015723:Gene Library; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000737:chemistry*; D011498:Protein Precursors / Q000737:chemistry; D012908:Snails / Q000378:metabolism*; D020866:omega-Conotoxin GVIA
D010456:Peptides, Cyclic; D011498:Protein Precursors; D004247:DNA; D020866:omega-Conotoxin GVIA