Contryphan‐Bt: A pyroglutamic acid containing conopeptide isolated from the venom of Conus betulinus

&NA; A new member of the contryphans family was isolated from the venom of Conus betilinus, a vermivorous species distributed in the South China Sea. Its sequence, ZSGCO(D‐W)KPWC‐NH2 (Z, pyroglutamic acid), was established by a combination of de novo MS/MS sequencing and venom‐duct transcriptome sequencing. The occurrence of D‐Trp6 was confirmed by chemical synthesis and HPLC behavior comparison. Like known contryphans, contryphan‐Bt produces the “stiff‐tail” syndrome in mice and contains one disulfide bond, a hydroxyproline, a D‐tryptophan, and an amidated C‐terminus. However, contryphan‐Bt differs from previously identified contryphans by a pyroglutamic acid at the N terminus. CD spectrum reveals that contryphan‐Bt possess &bgr;‐turn in solution. HighlightsA new member of the contryphan family, contryphan‐Bt was isolated from the venom of Conus betilinus.The sequence of contryphan‐Bt is ascertained as ZSGCO(D‐W)KPWC‐NH2 (Z, pyroglutamic acid).This finding is the first instance of the identification of pyroglutamic acid in contryphan.

[1]  P. Ascenzi,et al.  Solution structure of the cyclic peptide contryphan‐Vn, a Ca2+‐dependent K+ channel modulator , 2004, Biopolymers.

[2]  Chao Bian,et al.  High-throughput identification of novel conotoxins from the Chinese tubular cone snail (Conus betulinus) by multi-transcriptome sequencing , 2016, GigaScience.

[3]  P. Ascenzi,et al.  Contryphan-Vn: a modulator of Ca2+-dependent K+ channels. , 2003, Biochemical and biophysical research communications.

[4]  P. Balaram,et al.  Sequencing of T-superfamily conotoxins from Conus virgo: Pyroglutamic acid identification and disulfide arrangement by MALDI mass spectrometry , 2007, Journal of the American Society for Mass Spectrometry.

[5]  J. Rivier,et al.  Bromocontryphan: post-translational bromination of tryptophan. , 1997, Biochemistry.

[6]  R. Lewis,et al.  Anti-allodynic efficacy of the χ-conopeptide, Xen2174, in rats with neuropathic pain , 2005, Pain.

[7]  C. Schroeder,et al.  chi-Conopeptide pharmacophore development: toward a novel class of norepinephrine transporter inhibitor (Xen2174) for pain. , 2009, Journal of medicinal chemistry.

[8]  B. Olivera,et al.  The contryphans, a D-tryptophan-containing family of Conus peptides: interconversion between conformers. , 2009, The journal of peptide research : official journal of the American Peptide Society.

[9]  Lena Eliasson,et al.  The first gamma-carboxyglutamic acid-containing contryphan. A selective L-type calcium ion channel blocker isolated from the venom of Conus marmoreus. , 2004, The Journal of biological chemistry.

[10]  P. Ascenzi,et al.  Contryphan-Vn: a novel peptide from the venom of the Mediterranean snail Conus ventricosus. , 2001, Biochemical and biophysical research communications.

[11]  M. Remm,et al.  High-resolution picture of a venom gland transcriptome: case study with the marine snail Conus consors. , 2012, Toxicon : official journal of the International Society on Toxinology.

[12]  P. Balaram,et al.  Characterization of contryphans from Conus loroisii and Conus amadis that target calcium channels , 2006, Peptides.

[13]  R. Lewis.  Conotoxins: molecular and therapeutic targets. , 2009, Progress in molecular and subcellular biology.

[14]  P. Balaram,et al.  Rapid mass spectral identification of contryphans. Detection of characteristic peptide ions by fragmentation of intact disulfide-bonded peptides in crude venom. , 2007, Rapid communications in mass spectrometry : RCM.

[15]  R. Norton,et al.  The cyclic contryphan motif CPxXPXC, a robust scaffold potentially useful as an ω‐conotoxin mimic , 2000 .

[16]  R. Stöcklin,et al.  Molecular Phylogeny, Classification and Evolution of Conopeptides , 2012, Journal of Molecular Evolution.

[17]  R. Norton.  µ-Conotoxins as Leads in the Development of New Analgesics , 2010, Molecules.

[18]  R. Lewis,et al.  Anti-allodynic efficacy of the chi-conopeptide, Xen2174, in rats with neuropathic pain , 2004 .

[19]  I. Vetter,et al.  Conus Venom Peptide Pharmacology , 2012, Pharmacological Reviews.

[20]  David J. Craik,et al.  ConoServer: updated content, knowledge, and discovery tools in the conopeptide database , 2011, Nucleic Acids Res..

[21]  R. Norton,et al.  Solution structure of contryphan-R, a naturally occurring disulfide-bridged octapeptide containing D-tryptophan: comparison with protein loops. , 1999, Biochemistry.

[22]  Daniel S. Margulies,et al.  2015 Brainhack Proceedings , 2016, GigaScience.

[23]  O. Knapp,et al.  Conotoxins Targeting Neuronal Voltage-Gated Sodium Channel Subtypes: Potential Analgesics? , 2012, Toxins.

[24]  R. Norton,et al.  The cyclic contryphan motif CPxXPXC, a robust scaffold potentially useful as an omega-conotoxin mimic. , 2000, Biopolymers.

[25]  J. Rivier,et al.  A Novel Post-translational Modification Involving Bromination of Tryptophan , 1997, The Journal of Biological Chemistry.

[26]  B. Olivera,et al.  Contryphan Is a D-Tryptophan-containing Conus Peptide* , 1996, The Journal of Biological Chemistry.

[27]  R. Taft,et al.  Optimized deep-targeted proteotranscriptomic profiling reveals unexplored Conus toxin diversity and novel cysteine frameworks , 2015, Proceedings of the National Academy of Sciences.

[28]  R. Rajesh.  Novel M‐Superfamily and T‐Superfamily conotoxins and contryphans from the vermivorous snail Conus figulinus , 2015, Journal of peptide science : an official publication of the European Peptide Society.

[29]  Reena Halai,et al.  Conotoxins: natural product drug leads. , 2009, Natural product reports.

[30]  B. Olivera,et al.  A novel alpha conotoxin (alpha-PIB) isolated from C. purpurascens is selective for skeletal muscle nicotinic acetylcholine receptors. , 2007, Toxicon : official journal of the International Society on Toxinology.

[31]  D. Yoshikami,et al.  μ-Conotoxin PIIIA, a New Peptide for Discriminating among Tetrodotoxin-Sensitive Na Channel Subtypes , 1998, The Journal of Neuroscience.

[32]  B. Olivera,et al.  A novel D-leucine-containing Conus peptide: diverse conformational dynamics in the contryphan family. , 1999, The journal of peptide research : official journal of the American Peptide Society.

[33]  B. Olivera,et al.  Contryphans from Conus textile venom ducts. , 2001, Toxicon : official journal of the International Society on Toxinology.

[34]  E. Hawrot,et al.  Characterization of a novel alpha4/4-conotoxin, Qc1.2, from vermivorous Conus quercinus. , 2009, Acta biochimica et biophysica Sinica.