Structure-activity relationships for the interaction of bovine pancreatic trypsin inhibitor with an intracellular site on a large conductance Ca2+-activated K+ channel
Structure-activity relationships for the interaction of bovine pancreatic trypsin inhibitor with an intracellular site on a large conductance Ca2+-activated K+ channel
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DOI：
10.1021/bi992140v
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发表时间：
2000-02-29
期刊：
影响因子：
2.9
通讯作者：
Moczydlowski, E
中科院分区：
文献类型：
--
作者：
Favre, I;Moss, GWJ;Moczydlowski, E
大电导钙激活钾通道（BKCa）含有牛胰蛋白酶抑制剂（BPTI）的细胞内结合位点，BPTI是多种丝氨酸蛋白酶（SerP）的众所周知的抑制剂。为了研究这种相互作用的结构基础，我们研究了11个BPTI突变体的活性，使用单一的大鼠骨骼肌BKCa通道纳入平面脂质双层。所有的突变体在单通道水平上诱导离散的亚态事件。与BPTI的解离速率常数呈负相关的底物的停留时间表现出相对较小的变化（
Large conductance Ca2+-activated K+ channels (BKCa) contain an intracellular binding site for bovine pancreatic trypsin inhibitor (BPTI), a well-known inhibitor of various serine proteinase (SerP) enzymes. To investigate the structural basis of this interaction, we examined the activity of 11 BPTI mutants using single BKCa channels from rat skeletal muscle incorporated into planar lipid bilayers. All of the mutants induced discrete substate events at the single-channel level. The dwell time of the substate, which is inversely related to the dissociation rate constant of BPTI, exhibited relatively small changes (