Total synthesis and further characterization of the gamma-carboxyglutamate-containing "sleeper" peptide from Conus geographus venom.
The total synthesis of the Gla-containing "sleeper" peptide (Gly-Glu-Gla-Gla-Leu-Gln-Gla-Asn-Gln-Gla-Leu-Ile-Arg-Gla-Lys-Ser-Asn-NH2 ) from Conus geographus is described. A new strategy for the synthesis of acid-sensitive peptide amides was developed, which allowed complete deprotection and cleavage of the L-gamma-carboxyglutamate-containing peptide from the 2,4-dimethoxybenzhydrylamine resin. Synthetic sleeper peptide, after preparative high-performance liquid chromatography (HPLC) purification, was shown to be identical with the native peptide by all criteria (coelution experiments of HPLC, sequence analysis, and biological activity). In addition, a developmental switch in the behavioral symptoms induced by the peptide after intracerebral administration in mice was documented. At low doses of the peptide (4-30 pmol/g), a sleeplike state was induced in mice under 2 weeks old; in contrast, older mice became markedly hyperactive. It is proposed that, in the presence of Ca2+, the sleeper peptide assumes an alpha-helical configuration in which all the gamma-carboxyglutamate residues are located on the same side of the alpha-helix.
Rivier
J
J
Clayton Foundation Laboratories for Peptide Biology, Salk Institute, La Jolla, California 92037.
Galyean
R
R
Simon
L
L
Cruz
L J
LJ
Olivera
B M
BM
Gray
W R
WR
D015055:1-Carboxyglutamic Acid; D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D020916:Conotoxins; D007202:Indicators and Reagents; D051379:Mice; D008978:Mollusk Venoms / Q000138:chemical synthesis* / Q000494:pharmacology; D011487:Protein Conformation; D012890:Sleep / Q000187:drug effects
D020916:Conotoxins; D007202:Indicators and Reagents; D008978:Mollusk Venoms; D015055:1-Carboxyglutamic Acid; C055407:conotoxin GV