Robello M
Physics Department, University of Genoa, Italy.
Biochim Biophys Acta. 1989 Jan 30;978(2):179-84. doi: 10.1016/0005-2736(89)90112-0.
alpha-Latrotoxin, with a molecular weight 130,000, is the main component of black widow spider venom, and acts at the presynaptical level, inducing a notable release of neurotransmitters in the synapses of all vertebrates. In artificial lipid membranes, this neurotoxin induces the formation of cation-selective ionic channels, whose conductance depends on the intensity and direction of the applied potential. In fact, also in the presence of symmetrical solutions of potassium chloride, the voltage-current characteristics of the single channel strongly rectify. Such rectification, which depends on the concentration of the ions in solution, can be described by a one-site, one-ion model for a channel. The data fit provides the values of the three parameters describing the model. Moreover, a statistical analysis of the amplitude of the single channel, as a function of the concentration of potassium chloride, has made it possible to verify the consistency of the model used.
分子量为130,000的α- latrotoxin是黑寡妇蜘蛛毒液的主要成分，作用于突触前水平，可在所有脊椎动物的突触中诱导神经递质的显著释放。在人工脂质膜中，这种神经毒素可诱导阳离子选择性离子通道的形成，其电导率取决于所施加电位的强度和方向。实际上，即使在氯化钾对称溶液存在的情况下，单通道的电压-电流特性也会发生强烈整流。这种取决于溶液中离子浓度的整流作用，可以用通道的单位点、单离子模型来描述。数据拟合提供了描述该模型的三个参数的值。此外，对单通道幅度作为氯化钾浓度函数的统计分析，使得验证所使用模型的一致性成为可能。
