The effect of Huwentoxin-I on Ca(2+) channels in differentiated NG108-15 cells, a patch-clamp study.
Huwentoxin-I (HWTX-I), a 3.75 kDa peptide toxin isolated from the venom of the spider Selenocosmia huwena, was found to be a reversible presynaptic inhibitor by our previous work. Using whole-cell patch clamp methods, we found that HWTX-I had no significant effect on the TTX-sensitive Na(+) current or the delayed rectifier K(+) current (K(r)) in low-serum medium cultured NG108-15 cells, but High-Voltage-Activated Ca(2+) channel expressed in prostaglandin E(1) differentiated NG108-15 cells could be potently inhibited by HWTX-I (EC(50) approximately 100 nM), while it hardly affected low-voltage-activated Ca(2+) channel. Among types of high-voltage-activated Ca(2+) channel, HWTX-I selectively inhibited N-type Ca(2+) channel and had only very weak effect on L-type Ca(2+) channel in prostaglandin E(1) differentiated NG108-15 cells.
Peng
K
K
College of life science, Hunan Normal University, 410081, Hunan 410006, Changsha, People's Republic of China.
Chen
X D
XD
Liang
S P
SP
D000595:Amino Acid Sequence; D015220:Calcium Channels / Q000187:drug effects*; D020746:Calcium Channels, L-Type / Q000187:drug effects; D020864:Calcium Channels, N-Type / Q000187:drug effects; D015640:Ion Channel Gating; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000494:pharmacology*; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects; D030162:Reptilian Proteins; D015222:Sodium Channels / Q000187:drug effects; D013111:Spider Venoms / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D015220:Calcium Channels; D020746:Calcium Channels, L-Type; D020864:Calcium Channels, N-Type; D009498:Neurotoxins; D015221:Potassium Channels; D030162:Reptilian Proteins; D015222:Sodium Channels; D013111:Spider Venoms; C083624:huwentoxin I