Selective blocker of TTX-S VGSC(電壓門控鈉離子通道TTX-S選擇性阻斷劑)
Hainantoxin-III (HNTX-III) is a peptide that has been isolated from the venom of the Chinese bird spider Seleconosmia hainana. Hainantoxin-III specifically blocks mammalian neuronal tetrodotoxin-sensitive voltage-gated sodium channels (VGSCs). Hainantoxin III was found inactive on tetrodotoxin-resistant VGSCs and voltage-gated Ca2+channels (both high and low voltage-activated).
Hainantoxin-III strongly depressed the amplitude of rat DRG tetrodotoxin-sensitive Na+ currents with an IC50 value of 1.1 nM. Like Hainantoxin-IV, Hainantoxin-III causes a hyperpolarizing shift of about 10 mV in the voltage midpoint of steady-state Na+ channel inactivation. Similar to Huwentoxin-IV, Hainantoxin-III and Hainantoxin-IV do not affect the activation and inactivation kinetics of Na+ currents.
Hainantoxin-III inhibits Nav1.7 current amplitude without significantly altering the activation and inactivation kinetics.Hainantoxin-III increases the deactivation of the Nav1.7 current after extreme depolarizations. Hainantoxin-III seems to interact with site 4 and to trap the domain II voltage sensor in the closed state. The inhibition of Nav1.7 by hainantoxin-III is reversible upon washing, but no reversibility was observed for Hainantoxin-IV and Huwentoxin-IV.
Hainantoxin-III was shown to block Nav1.1, Nav1.2, Nav1.3 and Nav1.7 expressed in HEK293 cells with IC50 values of 1.27 µM, 275 nM, 491 nM and 232 nM, respectively.
二硫鍵：Cys2-Cys17, Cys9-Cys22, and Cys16-Cys29
長度 (aa)： 33
外觀： White lyophilized solid
可溶性：water and saline buffer
CAS 號：Not available
純度： > 97%