Molecular structure of the glibenclamide binding site of the β-cell KATP channel
Molecular structure of the glibenclamide binding site of the β-cell KATP channel
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DOI：
10.1016/s0014-5793(01)02538-8
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发表时间：
2001-06-15
期刊：
影响因子：
3.5
通讯作者：
Ashcroft, SJH
中科院分区：
文献类型：
--
作者：
Mikhailov, MV;Mikhailova, EA;Ashcroft, SJH
我们研究了胰腺β细胞ATP敏感性钾（K-ATP）通道的格列本脲结合位点的结构。KATP通道是由4个Kir6.2亚基和4个磺酰脲受体（SUR 1）亚基组成的复合物，SUR 1（ABCC 8）属于LTP结合盒蛋白家族，具有2个核苷酸结合域（NBD 1和NBD 2）和17个跨膜（TRI）序列。在杆状病毒表达系统中，NBD 1和TM 12之间的两部分SUR 1的共表达导致格列本脲结合活性恢复，而单独表达单个N-或C-末端部分均不产生格列本脲结合活性，证实了格列本脲结合位点的二价结构，通过使用N-末端截短的重组蛋白，我们已经表明，CL 3-TM 5和TM 6之间的胞质环-在IV-型胶原的形成中起关键作用。格列本脲结合位点的末端组分。对SUR 1 C-末端部分缺失变体的分析表明，CL 8（TM 15和TM 16之间的胞质环）是格列本脲结合位点C-末端组分的唯一决定因素。我们认为，在天然KATP通道的SUR 1中，CU和CL 8的紧密接近导致格列本脲结合位点的形成。(C)2001年由Elsevier Science B，V.代表欧洲生物化学学会联合会出版。
We have investigated the structure of the glibenclamide binding site of pancreatic beta -cell ATP-sensitive potassium (K-ATP) channels. KATP channels are a complex of four poreforming Kir6.2 subunits and four sulfonylurea receptor (SUR1) subunits, SUR1 (ABCC8) belongs to the;LTP binding cassette family of proteins and has two nucleotide binding domains (NBD1 and NBD2) and 17 putative transmembrane (TRI) sequences. Co-expression in a baculovirus expression system of two parts of SUR1 between NBD1 and TM12 leads to restoration of glibenclamide binding activity, whereas expression of either individual N- or C-terminal part alone gave no glibenclamide binding activity, confirming a bivalent structure of the glibenclamide binding site, By using N-terminally truncated recombinant proteins we hare shown that CL3 - the cytosolic loop between TM5 and TM6 - plays a key role in formation of the IV-terminal component of the glibenclamide binding site. Analysis of deletion variants of the C-terminal part of SUR1 showed that CL8 - the cytosolic loop between TM15 and TM16 - is the only determinant for the C-terminal component of the glibenclamide binding site. We suggest that in SUR1 in the native KATP channel close proximity of CU and CL8 leads to formation of the glibenclamide binding site. (C) 2001 Published by Elsevier Science B,V. on behalf of the Federation of European Biochemical Societies.