The cross channel activities of spider neurotoxin huwentoxin-I on rat dorsal root ganglion neurons.
In this paper, we investigated the action of huwentoxin-I (HWTX-I) purified from the venom of the Chinese bird spider Ornithoctonus huwena on Ca(2+), Na(+) channels of adult rat dorsal root ganglion (DRG) neurons. The results showed that huwentoxin-I could reduce the peak currents of N-type Ca(2+) channels (IC(50) approximately 100 nM) and TTX-S Na(+) channels (IC(50) approximately 55 nM), whereas no effect was detected on TTX-R Na(+) channels. The comparative studies indicated that the selectivity of HWTX-I on Ca(2+) channels was higher that of MVIIA and approximately the same as that of GVIA. HWTX-I is the first discovered toxin with the cross channel activities from the spider O. huwena venom similar to micro O-conotoxins MrVIA and MrVIB.
Wang
Meichi
M
Key Laboratory of Protein Chemistry and Developmental Biology of Education, The College of Life Science, Hunan Normal University, Changsha 410081, China.
Guan
Xin
X
Liang
Songping
S
D000595:Amino Acid Sequence; D000818:Animals; D020864:Calcium Channels, N-Type / Q000502:physiology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D015640:Ion Channel Gating / Q000187:drug effects; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D008969:Molecular Sequence Data; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009498:Neurotoxins / Q000235:genetics / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D030162:Reptilian Proteins / Q000235:genetics / Q000494:pharmacology*; D017386:Sequence Homology, Amino Acid; D015222:Sodium Channels / Q000502:physiology; D013111:Spider Venoms / Q000235:genetics / Q000494:pharmacology*; D013112:Spiders / Q000737:chemistry; D013779:Tetrodotoxin / Q000494:pharmacology
D020864:Calcium Channels, N-Type; D007473:Ion Channels; D009498:Neurotoxins; D030162:Reptilian Proteins; D015222:Sodium Channels; D013111:Spider Venoms; C083624:huwentoxin I; D013779:Tetrodotoxin