ORGANELLE TRANSPORT OF ION CHANNELS IN EXCITABLE CELLS

含有钾离子通道的小细胞器已从 鱿鱼巨轴突的轴浆。 这些制剂已被分馏 根据尺寸，使用控制孔径的玻璃珠柱。 两类 囊泡是用这种技术获得的：一类包括 直径约 150 nm 的囊泡，第二个包含 直径在 30-50 nm 范围内的相对较小的囊泡。 后者 制剂含有运动 ATP 酶、驱动蛋白和延迟整流器 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 轴突膜中离子通道的回收。 另一类是 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与较小的不同 囊泡，可能反映了由于降解而导致的通道变化， 或“老化”。 两类囊泡都不同于突触囊泡 它们也存在于轴浆中，并且显然正在转运到 和来自神经末梢。

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.