The polyamine binding site in inward rectifier K+ channels.
The polyamine binding site in inward rectifier K+ channels.
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DOI：
10.1085/jgp.200509467
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发表时间：
2006-05
期刊：
影响因子：
--
通讯作者：
Nichols CG
中科院分区：
文献类型：
--
作者：
Kurata HT;Marton LJ;Nichols CG
强内向整流钾通道表现出强有力的和陡峭的电压依赖性阻滞细胞内多胺。为了定位多胺结合位点，我们已经检查了多胺阻断对在强整流Kir通道（Kir6.2[N160 D]）的孔中策略性取代的半胱氨酸残基的MTSEA修饰速率的影响。精胺仅保护在孔中的深位置处取代的半胱氨酸，在“整流控制器”残基（Kir6.2中的N160 D，Kir2.1中的D172）和选择性过滤器之间，对抗MTSEA修饰。相比之下，用较长的合成多胺（CGC-11179）阻断也保护在更靠近通道的细胞质入口的位点处取代的半胱氨酸。在内腔入口处的半胱氨酸（169 C）的修饰不受精胺或CGC-11179的影响，并且精胺被清楚地“锁定”到内腔中（即，表现出明显更慢的排出速率）。这些数据提供了对精胺结合位点的物理限制，表明精胺在超出“整流控制器”残留物的深层位点处稳定结合，靠近通道的细胞外入口。
Strongly inwardly rectifying potassium channels exhibit potent and steeply voltage-dependent block by intracellular polyamines. To locate the polyamine binding site, we have examined the effects of polyamine blockade on the rate of MTSEA modification of cysteine residues strategically substituted in the pore of a strongly rectifying Kir channel (Kir6.2[N160D]). Spermine only protected cysteines substituted at a deep location in the pore, between the “rectification controller” residue (N160D in Kir6.2, D172 in Kir2.1) and the selectivity filter, against MTSEA modification. In contrast, blockade with a longer synthetic polyamine (CGC-11179) also protected cysteines substituted at sites closer to the cytoplasmic entrance of the channel. Modification of a cysteine at the entrance to the inner cavity (169C) was unaffected by either spermine or CGC-11179, and spermine was clearly “locked” into the inner cavity (i.e., exhibited a dramatically slower exit rate) following modification of this residue. These data provide physical constraints on the spermine binding site, demonstrating that spermine stably binds at a deep site beyond the “rectification controller” residue, near the extracellular entrance to the channel.
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影响因子：
3.8
作者：
Guo, Donglin;Lu, Zhe
通讯作者：
Lu, Zhe
DOI：
10.1085/jgp.117.5.395
发表时间：
2001-05
期刊：
The Journal of general physiology
影响因子：
--
作者：
Guo D;Lu Z
通讯作者：
Lu Z
影响因子：
25
作者：
Pegan, S;Arrabit, C;Choe, S
通讯作者：
Choe, S
影响因子：
3.6
作者：
Loussouarn, G;Marton, LJ;Nichols, CG
通讯作者：
Nichols, CG
影响因子：
5.5
作者：
Makary, SMY;Claydon, TW;Boyett, MR
通讯作者：
Boyett, MR