Abe T, Koyano K, Saisu H, Nishiuchi Y, Sakakibara S
Neurosci Lett. 1986 Nov 11;71(2):203-8. doi: 10.1016/0304-3940(86)90559-8.
The binding of radioiodinated omega-conotoxin GVIA, a probable Ca channel antagonist, to synaptic plasma membranes of rat brain was examined. Two kinds of specific binding sites were found with apparent dissociation constants of 10 pM and 0.5 nM and maximum binding capacities of 0.5 and 3.4 pmol/mg prot., respectively. The binding of the toxin was not affected by high concentrations of Ca antagonists or an agonist, indicating distinct binding sites of the toxin from those of these drugs. Divalent and trivalent metal ions strongly inhibited the binding. The order of their inhibitory potencies was similar to that for inhibition of the Ca current through certain Ca channels. These results suggest that the binding sites of omega-conotoxin GVIA are functionally related to the Ca2+-binding site postulated to be in the pore of the Ca channel.
对放射性碘化的ω-芋螺毒素GVIA（一种可能的钙通道拮抗剂）与大鼠脑突触质膜的结合进行了研究。发现了两种特异性结合位点，其表观解离常数分别为10 pM和0.5 nM，最大结合容量分别为0.5和3.4 pmol/mg蛋白。毒素的结合不受高浓度钙拮抗剂或激动剂的影响，表明毒素的结合位点与这些药物的结合位点不同。二价和三价金属离子强烈抑制结合。它们的抑制效力顺序与通过某些钙通道抑制钙电流的顺序相似。这些结果表明，ω-芋螺毒素GVIA的结合位点在功能上与假定存在于钙通道孔中的钙结合位点相关。
