IS THE C-TERMINAL ARM OF LENS GAP JUNCTION CHANNEL PROTEIN THE CHANNEL GATE
IS THE C-TERMINAL ARM OF LENS GAP JUNCTION CHANNEL PROTEIN THE CHANNEL GATE
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DOI：
10.1016/0006-291x(85)90959-3
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发表时间：
1985-01-01
影响因子：
3.1
通讯作者：
GIRSCH, SJ
中科院分区：
文献类型：
--
作者：
PERACCHIA, C;GIRSCH, SJ
透镜间隙连接通道在一个重组系统中进行研究，该系统通过将透镜连接蛋白（MIP26）及其缺少c端臂的胰蛋白酶裂解产物（MIP21）纳入脂质体中，无论是否含有钙调素。用渗透膨胀法研究通道渗透性。MIP26和MIP21脂质体在蔗糖或聚乙二醇中存在或不存在Ca++表明存在大通道。在没有Ca++的情况下，MIP26和MIP21脂质体在两种渗透剂中均表现良好。在ca++中，mip26 -钙调蛋白脂质体在两种渗透中都不会膨胀，表明通道完全关闭，而mip21 -钙调蛋白脂质体在蔗糖中膨胀，但在聚乙二醇中不会。这表明c端臂参与通道门控。
Lens gap junction channels are studied in a reconstituted system obtained by incorporating into liposomes, with or without calmodulin, the lens junction protein (MIP26) and its trypsin-cleaved product (MIP21) that lacks the C-terminal arm. Channel permeability is studied with an osmotic swelling assay. MIP26 and MIP21 liposomes swell in sucrose or polyethyleneglycol with or without Ca++ indicating the presence of large channels. Without Ca++, MIP26 and MIP21 liposomes well in both permeants. With Ca++, MIP26-calmodulin liposomes do not swell in either permeant, indicating complete channel closure, while MIP21-calmodulin liposomes swell in sucrose but not in polyethyleneglycol. This suggests that the C-terminal arm participates in channel gating.