ORGANELLE TRANSPORT OF ION CHANNELS IN EXCITABLE CELLS

含有钾离子通道的小细胞器已经从 鱿鱼巨大轴突的轴浆。 这些制剂已被分馏 基于尺寸与控制孔径玻璃珠柱。 两类 用这种技术获得囊泡：一类由 直径约150 nm的囊泡，和第二个含有 直径在30-50 nm范围内的相对小的囊泡。 后者 含有运动ATP酶、驱动蛋白和延迟整流蛋白的制剂 钾离子通道，类似于轴突中的延迟整流器 基于免疫印迹的膜和这些囊泡的掺入 人工脂质双层。 这些囊泡似乎参与了 轴突膜中离子通道的再循环。 另一类 囊泡很可能起源于内吞作用。 它们还含有钾 离子通道免疫反应性，其不同于较小的 囊泡，可能反映了由于降解导致的通道变化， 或“老化”。 这两类囊泡都不同于突触囊泡 它们也存在于轴浆中， 和神经末梢。

Small organelles containing potassium ion channels have been isolated from axoplasm of squid giant axons. These preparations have been fractionated based on size with a control pore size glass bead column. Two classes of vesicles are obtained with this technique: one class consisting of vesicles approximately 150 nm in diameter, and a second containing relatively small vesicles in the 30-50 nm diameter range. The latter preparations contain the motor ATPase, kinesin, and the delayed rectifier potassium ion channel, similar to the delayed rectifier in the axonal membrane based on immunoblots and incorporation of these vesicles in artificial lipid bilayers. These vesicles appear to be involved in the recycling of ion channels in the axonal membrane. The other class of vesicles may well be endocytotic in origin. They also contain potassium ion channel immunoreactivity which differs from that of the smaller vesicles, possibly reflecting changes in the channel due to degradation, or "aging". Both classes of vesicles are distinct from synaptic vesicles which are also found in axoplasm and which are apparently in transit to and from the nerve terminal.