BLACK-WIDOW SPIDER VENOM - EFFECT OF PURIFIED TOXIN ON LIPID BILAYER MEMBRANES
BLACK-WIDOW SPIDER VENOM - EFFECT OF PURIFIED TOXIN ON LIPID BILAYER MEMBRANES
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DOI：
10.1126/science.948756
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发表时间：
1976-01-01
期刊：
影响因子：
56.9
通讯作者：
TZENG, MC
中科院分区：
文献类型：
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作者：
FINKELSTEIN, A;RUBIN, LL;TZENG, MC
将来自黑寡妇蜘蛛毒液的纯化毒素（B5级分）添加到脂质双层膜的一侧上的溶液中，与膜不可逆地相互作用，以产生膜电导随时间的连续线性上升。最终可以获得大于10-4欧姆/厘米2的倒数的电导，而不损失膜的稳定性。用毒素处理的膜对碱金属阳离子的选择性优于阴离子，并且基本上可渗透Ca 2+。毒素的这些作用是由于在膜中形成永久性的通道，这些通道具有均匀的电导率，3.6 × 104。10-10倒数欧姆（在0.1 M KCl中），几乎一直保持打开。二价阳离子的渗透性和较小的电导在低pH值的毒素处理的膜表明，有负电荷（可能从羧基）与通道。这种毒素对脂双层膜的作用可能与其刺激神经肌肉接头处大量释放递质的能力有关，并对组织培养的神经元产生深刻的形态学变化。
A purified toxin (the B5 fraction) from black widow spider venom added to the solution on 1 side of a lipid bilayer membrane interacts irreversibly with the membrane to produce a continuous, linear rise of membrane conductance with time. Conductances greater than 10-4 reciprocal ohm/cm2 can eventually be attained without any loss of membrane stability. Membranes treated with toxin are ideally selective for alkali cations over anions and are substantially permeable to Ca2+. These effects of the toxin result from the formation of permanent channels in the membrane of uniform conductance, 3.6 .times. 10-10 reciprocal ohm (in 0.1 M KCl), that remain open almost all the time. Both the divalent cation permeability and the smaller conductances at low pH of toxin-treated membranes suggest that there is negative charge (possibly from carboxyl groups) associated with the channels. The possible relation of the action of this toxin on lipid bilayer membranes to its ability to stimulate massive transmitter release at the neuromuscular junction and to produce profound morphological changes on tissue cultured neurons is discussed.