A study of reconstituted anion channels using lipid bilayers

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• 作者：Tripathy ; A. ; Ti Tien ; H. ; Ottova ; Angelica L.
• 关键词：Chloride channel ; Planar lipid bilayer ; BLM ; Liposomes ; Permeability ; BLM ; Bilayer lipid membrane ; ER ; Endoplasmic reticulum ; SR ; Sarcoplasmic reticulum ; DIDS ; 4 ; 4&prime ; -diisothiocyanostilbene-2 ; 2&prime ; -disulfonic acid
• 刊名：Bioelectrochemistry and Bioenergetics
• 出版年：1998
• 出版时间：January, 1998
• 年：1998
• 卷：44
• 期：2
• 页码：183-199
• 全文大小：1.55 M

文摘

A chloride channel from impermeant sarcoplasmic reticulum (SR) was embedded in a planar lipid bilayer (BLM) and its electrical properties determined. Studies using ER-derived vesicles fused with BLMs have shown that they are permeable to Na⁺, K⁺, choline and Cl⁻ but less permeable to Ca²⁺ and Mg²⁺. Though highly permeable to K⁺, the liver ER membrane has been postulated to a lack of an efficient ion-conducting structure for K⁺ channel in the SR. The present study was undertaken with the aim to look at the anionic, Ca²⁺ and K⁺ permeability pathways present in the ER membrane. Our reconstituted system exhibits considerable anionic permeability following the sequence: SCN⁻ > I⁻ > Br⁻ Cl⁻ > gluconate. The findings suggest the chloride channels have low field-strength sites. It can be pharmacologically dissected to Zn²⁺-sensitive and DIDS-sensitive types. The gating of the channel is weakly voltage-dependent and at higher positive or negative voltages the channel prefers the low sub-conductance states.