Discovery of a Novel Nav1.7 Inhibitor From Cyriopagopus albostriatus Venom With Potent Analgesic Efficacy

Abstract

Spider venoms contain a vast array of bioactive peptides targeting ion channels. A large number of peptides have high potency and selectivity toward sodium channels. Nav1.7 contributes to action potential generation and propagation and participates in pain signaling pathway. In this study, we describe the identification of μ-TRTX-Ca2a (Ca2a), a novel 35-residue peptide from the venom of Vietnam spider Cyriopagopus albostriatus (C. albostriatus) that potently inhibits Nav1.7 (IC50 = 98.1 ± 3.3 nM) with high selectivity against skeletal muscle isoform Nav1.4 (IC50 > 10 μM) and cardiac muscle isoform Nav1.5 (IC50 > 10 μM). Ca2a did not significantly alter the voltage-dependent activation or fast inactivation of Nav1.7, but it hyperpolarized the slow inactivation. Site-directed mutagenesis analysis indicated that Ca2a bound with Nav1.7 at the extracellular S3–S4 linker of domain II. Meanwhile, Ca2a dose-dependently attenuated pain behaviors in rodent models of formalin-induced paw licking, hot plate test, and acetic acid-induced writhing. This study indicates that Ca2a is a potential lead molecule for drug development of novel analgesics.

Two Novel Peptide Toxins from the Spider Cyriopagopus longipes Inhibit Tetrodotoxin-Sensitive Sodium Channels

“…In this study, two novel 33-residue peptide toxins, namely μ-THTX-Cl6a (Cl6a) and μ-THTX-Cl6b (Cl6b), were isolated from the venom of the spider Cyriopagopus longipes and were shown to significantly reduce currents of the TTX-S channel with high affinity against NaV1.7. The mechanism underlying Cl6b activity on NaV1.7 was found to be similar to other previously reported NaV1.7-peptide inhibitors, i.e., by direct binding to the domain II segments S3–S4 (DII S3–S4) of NaV1.7 [ 5 , 19 , 25 , 27 , 28 ]. Cl6a and Cl6b showed strong binding kinetics which were linked to sustained NaV1.7 inhibition.…”

Structure–Function and Therapeutic Potential of Spider Venom-Derived Cysteine Knot Peptides Targeting Sodium Channels

“…The NaSpTx3 peptides Gr1b and Gr2c reversed acute and inflammatory pain intrathecally (Lampe, 1998), while ProTx-II and its optimized analog JNJ63955918 reversed neuropathic and inflammatory pain when administered intrathecally or locally (Tanaka et al, 2015; Flinspach et al, 2017). The NaSpTx1 peptides HwTx-IV and HNTX-IV also reversed neuropathic and inflammatory pains intraperitonially (Liu et al, 2014a,b), while ides Ca2a and cyriotoxin-1a reversed inflammatory and thermal pain following intraperitoneal or intraplantar administration, respectively (Zhang et al, 2018a; Goncalves et al, 2019).…”

Newly Discovered Action of HpTx3 from Venom of Heteropoda venatoria on Nav1.7 and Its Pharmacological Implications in Analgesia

“…cDNAs encoding rat Na v 1.2, rat Na v 1.3, human Na v 1.5, and mouse Na v 1.6 were subcloned into the vector pcDNA3.1; cDNA encoding rat Na v 1.4 was subcloned into the vector pRGB4; cDNA encoding human Na v 1.7 was subcloned into the vector pcDNA3.1-mod; cDNAs encoding rat Na v 1.8 and human Na v 1.9 were subcloned into the vectors pCMV-HA and pEGFP-N1, respectively. For localizing the binding sites of HpTx3 on the Na v 1.7 and therefore probing the its mechanism of action, several chimeras were constructed with a recombination strategy by replacing the extracellular loop S3b-S4 in domain II, domain III, and domain IV of Na v 1.7 with the counterpart sequences of Na v 1.8, respectively, using the methods described [42,73,74]. As a result, three chimeras were prepared, namely, Na v 1.7/1.8DIIS3b-S4, Na v 1.7/1.8DIII, and Na v 1.7/1.8 DIV.…”