Contryphans an unusual Conus peptides which contain a distinctive post-tran
slational modification, D-tryptophan or D-leucine. cDNA clones encoding new
contryphans from the mollusc-hunting cone snail Conus textile were identif
ied and the inferred mature peptides were synthesized: contryphan-Tx (Glp-C
ys-Hyp-D-Trp-Gln-Pro-Tyr-Cys-NH2), Leu-contryphan-Tx (Cys-Val-D-Leu-Tyr-Pro
-Trp-Cys-NH2) and contryphan R/Tx which is identical to contryphan-R [Jimen
ez et al., 1996. Contryphan is a D-tryptophan containing Conus peptide. J.
Biol. Chem. 281, 78002-28005], Leu-contryphan-Tx exhibits a single peak, bu
t contryphan-Tx shows two peaks under reverse-phase high-performance liquid
chromatography conditions. Ultraviolet resonance Raman spectroscopy demons
trates a difference in the D-tryptophan dihedral angle for the two contryph
an-Tx equilibrium conformers. Both the sequences and in vivo effects of all
contryphans isolated suggest that there are two major branches of the cont
ryphan family. (C) 2001 Elsevier Science Ltd. All rights reserved.