Permeability of reconstituted sarcoplasmic reticulum vesicles. Reconstitution of the K+, Na+ channel.
Permeability of reconstituted sarcoplasmic reticulum vesicles. Reconstitution of the K+, Na+ channel.
复制标题
重建肌浆网囊泡的渗透性。
DOI：
10.1016/0005-2736(81)90466-1
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Meissner,G
中科院分区：
文献类型：
--
作者：
Young,RC;Allen,R;Meissner,G
用电压敏感探针3，3′-二戊基-2，2 ′-氧碳菁测定[3 H]菊粉、[3 H]胆碱+、86 Rb+和22 Na+的外排率以及膜电位的变化来表征重组兔骨骼肌肌浆网囊泡的通透性。天然囊泡与脱氧胆酸盐解离，并通过透析重建。Ca 2+的积累部分恢复。约1/2的重构囊泡被发现是“渗漏的”，即，可渗透胆碱+或Tris+，但不渗透菊粉。剩余的重构囊泡是“密封的”，即胆碱+、Tris+和菊粉不可渗透。封闭的重组囊泡可根据其K+、Na+渗透性进一步细分。约12，以前指定的I型，容易渗透到K+和Na+，表明肌浆网的K+，Na+通道的存在。剩余的密封囊泡（II型）对K+和Na+形成了渗透屏障，表明它们缺乏K+、Na+通道。这些研究表明，肌浆网的K ~+、Na ~+通道可被去污剂增溶，并能重建而保持活性。此外，我们的研究结果表明，部分或全部的重构囊泡的Ca 2+-负载效率的降低可能是由于存在一个显着的部分渗漏囊泡。
Permeability properties of reconstituted rabbit skeletal muscle sarcoplasmic reticulum vesicles were characterized by measuring efflux rates of [3 H] inulin,[3 H] choline+, 86 Rb+, and 22 Na+, as well as membrane potential changes using the voltage-sensitive probe, 3, 3′-dipentyl-2, 2′-oxacarbocyanine. Native vesicles were dissociated with deoxycholate and were reconstituted by dialysis. Energized Ca 2+ accumulation was partially restored. About 1 2 of the reconstituted vesicles were found to be ‘leaky’, ie, permeable to choline+ or Tris+ but not to inulin. The remaining reconstituted vesicles were ‘sealed’, ie, impermeable to choline+, Tris+ and inulin. Sealed reconstituted vesicles could be further subdivided according to their K+, Na+ permeability. About 1 2, previously designated Type I, were readily permeable to K+ and Na+, indicating the presence of the K+, Na+ channel of sarcoplasmic reticulum. The remaining sealed vesicles (Type II) formed a permeability barrier to K+ and Na+, suggesting that they lacked the K+, Na+ channel. These studies show that the K+, Na+ channel of sarcoplasmic reticulum can be solubilized with detergent and reconstituted with retention of activity. Furthermore, our results suggest that part or all of the decreased Ca 2+-loading efficiency of reconstituted vesicles may be due to the presence of a significant fraction of leaky vesicles.