Uncovering Intense Protein Diversification in a Cone Snail Venom Gland Using an Integrative Venomics Approach

Marine cone snail venoms are highly complex mixtures of peptides and proteins. They have been studied in-depth over the past 3 decades, but the modus operandi of the venomous apparatus still remains unclear. Using the fish-hunting Conus consors as a model, we present an integrative venomics approach, based on new proteomic results from the venom gland and data previously obtained from the transcriptome and the injectable venom. We describe here the complete peptide content of the dissected venom by the identification of numerous new peptides using nanospray tandem mass spectrometry in combination with transcriptomic data. Results reveal extensive mature peptide diversification mechanisms at work in the venom gland. In addition, by integrating data from three different venom stages, transcriptome, dissected, and injectable venoms, from a single species, we obtain a global overview of the venom processing that occurs from the venom gland tissue to the venom delivery step. In the light of the successive steps in this venom production system, we demonstrate that each venom compartment is highly specific in terms of peptide and protein content. Moreover, the integrated investigative approach discussed here could become an essential part of pharmaceutical development, as it provides new potential drug candidates and opens the door to numerous analogues generated by the very mechanisms used by nature to diversify its peptide and protein arsenal

Uncovering Intense Protein Diversification in a Cone Snail Venom Gland Using an Integrative Venomics Approach

Marine cone snail venoms are highly complex mixtures of peptides and proteins. They have been studied in-depth over the past 3 decades, but the modus operandi of the venomous apparatus still remains unclear. Using the fish-hunting Conus consors as a model, we present an integrative venomics approach, based on new proteomic results from the venom gland and data previously obtained from the transcriptome and the injectable venom. We describe here the complete peptide content of the dissected venom by the identification of numerous new peptides using nanospray tandem mass spectrometry in combination with transcriptomic data. Results reveal extensive mature peptide diversification mechanisms at work in the venom gland. In addition, by integrating data from three different venom stages, transcriptome, dissected, and injectable venoms, from a single species, we obtain a global overview of the venom processing that occurs from the venom gland tissue to the venom delivery step. In the light of the successive steps in this venom production system, we demonstrate that each venom compartment is highly specific in terms of peptide and protein content. Moreover, the integrated investigative approach discussed here could become an essential part of pharmaceutical development, as it provides new potential drug candidates and opens the door to numerous analogues generated by the very mechanisms used by nature to diversify its peptide and protein arsenal

Engineering Potent and Selective Analogues of GpTx-1, a Tarantula Venom Peptide Antagonist of the Na_V1.7 Sodium Channel

Na_V1.7 is a voltage-gated sodium ion channel implicated by human genetic evidence as a therapeutic target for the treatment of pain. Screening fractionated venom from the tarantula Grammostola porteri led to the identification of a 34-residue peptide, termed GpTx-1, with potent activity on Na_V1.7 (IC₅₀ = 10 nM) and promising selectivity against key Na_V subtypes (20× and 1000× over Na_V1.4 and Na_V1.5, respectively). NMR structural analysis of the chemically synthesized three disulfide peptide was consistent with an inhibitory cystine knot motif. Alanine scanning of GpTx-1 revealed that residues Trp²⁹, Lys³¹, and Phe³⁴ near the C-terminus are critical for potent Na_V1.7 antagonist activity. Substitution of Ala for Phe at position 5 conferred 300-fold selectivity against Na_V1.4. A structure-guided campaign afforded additive improvements in potency and Na_V subtype selectivity, culminating in the design of [Ala5,Phe6,Leu26,Arg28]­GpTx-1 with a Na_V1.7 IC₅₀ value of 1.6 nM and >1000× selectivity against Na_V1.4 and Na_V1.5