Phrixotoxin 2 

Phrixotoxin 2 is a Kv4 family potassium channel inhibitor, with K_i values in rats of 120 nM for Kv4.2, 110 nM for Kv4.3, and 230 nM for Kv4.1. Phrixotoxin 2 mediates voltage-dependent inhibition of Kv4.2 and Kv4.3 currents, and voltage-independent inhibition of Kv4.1 currents. Phrixotoxin 2 fails to inhibit A-type K⁺ currents in visceral dorsal root ganglion neurons. Phrixotoxin 2 induces contraction of non-pregnant uterine smooth muscle and triggers orofacial cold hyperalgesia in rats. Phrixotoxin 2 can distinguish the contribution of Kv4 subunits to A-type K⁺ currents in different subsets of sensory neurons. Phrixotoxin 2 can be used in research related to chronic pain and trigeminal neuropathic pain^[1][2][3].

Phrixotoxin 2 (4-7 min) inhibits voltage-independently and concentration-dependently the K_A currents in capsaicin-sensitive C-fiber afferent neurons among IB4-strongly stained rat L6-S1 dorsal root ganglion (DRG) somata, but exerts no effect on the K_A currents in FB-positive capsaicin-sensitive C-fiber afferent neurons innervating the bladder^[1].
Phrixotoxin 2 (200-500 nM; 4-7 min) inhibits the currents of heterologously expressed rat Kv4.1, Kv4.2 and Kv4.3 in CHO-K1 cells with distinct voltage dependence, which is determined by a four-amino-acid region at the carboxyl terminus of the S3 transmembrane domain; Kv4.1 exhibits voltage-independent inhibition (K_i = 230 nM at +30 mV), while Kv4.2 and Kv4.3 show voltage-dependent inhibition (K_i values of 120 nM and 110 nM, respectively, at +30 mV)^[1].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Phrixotoxin 2 (2 mM, 50 µL; i.c.; single bilateral injection in orofacial regions) induces orofacial cold hypersensitivity to noxious 5°C stimulation in normal rats, as evidenced by reduced total contact time and total contact numbers in operant behavioral tests^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

3921.69

C₁₆₉H₂₅₉N₄₉O₄₃S₈

741738-57-8

Tyr-Cys-Gln-Lys-Trp-Met-Trp-Thr-Cys-Asp-Glu-Glu-Arg-Lys-Cys-Cys-Glu-Gly-Leu-Val-Cys-Arg-Leu-Trp-Cys-Lys-Arg-Ile-Ile-Asn-Met-NH2 (Disulfide Bridge: Cys2-Cys16, Cys9-Cys21, Cys15-Cys25)

YCQKWMWTCDEERKCCEGLVCRLWCKRIINM-NH2 (Disulfide Bridge: Cys2-Cys16, Cys9-Cys21, Cys15-Cys25)

Room temperature in continental US; may vary elsewhere.

Please store the product under the recommended conditions in the Certificate of Analysis.

• [1]. Yunoki T, et al. Differential contribution of Kv4-containing channels to A-type, voltage-gated potassium currents in somatic and visceral dorsal root ganglion neurons. J Neurophysiol. 2014 Nov 15;112(10):2492-504.  [Content Brief]

  [2]. Smith RC, et al. The role of voltage-gated potassium channels in the regulation of mouse uterine contractility. Reproductive biology and endocrinology : RB&E. 2007 Nov 02;5:41.  [Content Brief]

  [3]. Kanda H, et al. Kv4.3 Channel Dysfunction Contributes to Trigeminal Neuropathic Pain Manifested with Orofacial Cold Hypersensitivity in Rats. The Journal of neuroscience : the official journal of the Society for Neuroscience. 2021 Mar 10;41(10):2091-2105.  [Content Brief]