Ben Khalifa R, Stankiewicz M, Pelhate M, Serrano-Hernandez S E, Possani L D, Hinkel H, Mebs D
Laboratory of Neurophysiology, CNRS EREA 120, Faculty of Medicine, University of Angers, France.
Toxicon. 1997 Jul;35(7):1069-80. doi: 10.1016/s0041-0101(96)00221-8.
A toxin named babycurus-toxin 1 (mol. wt 8191), from telson extracts of the scorpion Babycurus centrurimorphus, was found to depolarize the cockroach giant axon. It progressively blocked the evoked action potentials after a short period of limited repetitive activity and after 30 min of toxin action it became impossible to evoke responses to current stimulations. Voltage-clamp experiments on the sodium current indicated that the toxin in micromolar concentrations progressively decreased the transient inward peak sodium current, but also slowed the activation phase of this sodium current and maintained an inward current during the voltage pulses, which deactivated slowly. The toxin also induced in the insect axon a slowly activating-deactivating component of the sodium current. This suggests that the toxin modifies both activation and inactivation mechanisms of sodium channels. Thus there is some similarity in the electrophysiological effects between BcTx1 and the beta-toxins active on mammals.
从蝎子Centruroides gracilis尾节提取物中发现的一种名为Centruroides gracilis毒素1(分子量8191)的毒素,可使蟑螂巨轴突去极化。在短时间有限的重复活动后,它逐渐阻断诱发的动作电位,毒素作用30分钟后,就无法诱发对电流刺激的反应。对钠电流进行的电压钳实验表明,微摩尔浓度的毒素会逐渐降低瞬时内向峰值钠电流,但也会减慢该钠电流的激活阶段,并在电压脉冲期间维持内向电流,该电流失活缓慢。该毒素还在昆虫轴突中诱导出一种缓慢激活-失活的钠电流成分。这表明该毒素改变了钠通道的激活和失活机制。因此,Centruroides gracilis毒素1(BcTx1)与对哺乳动物有活性的β毒素在电生理效应上存在一些相似性。