Potency optimization of Huwentoxin-IV on hNav1.7: A neurotoxin TTX-S sodium-channel antagonist from the venom of the Chinese bird-eating spider Selenocosmia huwena

• Published in: Peptides (New York, N.Y. : 1980) Vol. 44; pp. 40 - 46
• Main Authors: Revell, Jefferson D., Lund, Per-Eric, Linley, John E., Metcalfe, Jacky, Burmeister, Nicole, Sridharan, Sudharsan, Jones, Clare, Jermutus, Lutz, Bednarek, Maria A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2013
• Subjects: Amino Acid Sequence; Amino Acid Substitution; Animals; antagonists; Araneae; electrophysiology; HEK293 Cells; Humans; Huwentoxin-IV; Hydrophobic and Hydrophilic Interactions; inhibitory concentration 50; Membrane Potentials - drug effects; Models, Molecular; Molecular Sequence Data; mutation; Nav1.7; NAV1.7 Voltage-Gated Sodium Channel - metabolism; Neuropathic; neurotoxins; Nociceptive; pain; peptides; Protein Structure, Secondary; Protein Structure, Tertiary; Selenocosmia huwena; sodium channels; Spider toxin; Spider Venoms - chemical synthesis; Spider Venoms - chemistry; Spider Venoms - pharmacology; Spiders; Structure-Activity Relationship; Synthetic peptide; venoms; Voltage-gated sodium channel; Voltage-Gated Sodium Channel Blockers - chemical synthesis; Voltage-Gated Sodium Channel Blockers - chemistry; Voltage-Gated Sodium Channel Blockers - pharmacology; DMSO; MeCN; CHO; TFA; HwTx-IV; Voltage-gated sodium channel; BSA; EDT; KCl; Pbf; FBS; IC50; Trt; HOBt; PBS; UV; MgCl2; Tris–HCl; EGTA; HwTx; CsF; NaCl; Synthetic peptide; nm; SAR; CO2; NaOH; CNS; CsOH; Neuropathic; Nociceptive; DMEM; CaCl2; TTX-S; Fmoc; ESI; DMF; GSH; DIC; CD; GSSG; ACF; KOH; PTFE; tBu; EDTA; RP-HPLC; ICK; LC/MS; Nav1.7; NMP; HEPES; Spider toxin; Huwentoxin-IV; TIS
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/j.peptides.2013.03.011

•Venom peptide Huwentoxin-IV is potent antagonist of hNav1.7 (IC50=17nM determined herein).•Nav1.7 is involved in generation and conduction of neuropathic and nociceptive pain.•We prepared Huwentoxin-IV analogs through a structure–function study.•Residues Glu1, Glu4, Phe6 and Tyr33 were revealed as important activity modulators.•Peptide 47 is significantly more potent (45-fold) than Huwentoxin-IV on hNav1.7. The spider venom peptide Huwentoxin-IV (HwTx-IV) 1 is a potent antagonist of hNav1.7 (IC50 determined herein as 17±2nM). Nav1.7 is a voltage-gated sodium channel involved in the generation and conduction of neuropathic and nociceptive pain signals. We prepared a number of HwTx-IV analogs as part of a structure–function study into Nav1.7 antagonism. The inhibitory potency of these analogs was determined by automated electrophysiology and is reported herein. In particular, the native residues Glu1, Glu4, Phe6 and Tyr33 were revealed as important activity modulators and several peptides bearing mutations in these positions showed significantly increased potency on hNav1.7 while maintaining the original selectivity profile of the wild-type peptide 1 on hNav1.5. Peptide 47 (Gly1, Gly4, Trp33-HwTx) demonstrated the largest potency increase on hNav1.7 (IC50 0.4±0.1nM).