Effects of hydroxyl radical and sulfhydryl reagents on the open probability of the purified cardiac ryanodine receptor channel incorporated into planar lipid bilayers
Effects of hydroxyl radical and sulfhydryl reagents on the open probability of the purified cardiac ryanodine receptor channel incorporated into planar lipid bilayers
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DOI：
10.1006/bbrc.1998.9244
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发表时间：
1998-08-28
影响因子：
3.1
通讯作者：
Nakayama, H
中科院分区：
文献类型：
--
作者：
Anzai, K;Ogawa, K;Nakayama, H
我们研究了羟基自由基对肌浆网钙释放通道——ryanodine受体离子通透性的影响。从猪心脏中分离得到的心脏良嘌呤受体重组为蛋白脂质体，并将其整合到平面双层膜中。在900/200 mM（顺式/反式）KCl中，单通道活性为724 pS，离子选择性为P-K:P-CI = 1:0.08。这些特征与通过肌浆网小泡合并通道所观察到的相似。H2O2与Cu（乙二胺）(2)在顺式腔室化学反应产生的羟基自由基增加了通道的打开概率。顺式室的SH氧化剂也增加了打开的可能性，而SH还原剂二硫代苏糖醇则逆转了这一作用。这些发现表明，羟基自由基与一些ryanodine受体的SH基团反应，并通过ryanodine受体增加Ca2+从肌浆网释放。(C) 1998学术出版社。
We examined the effects of hydroxyl radical on the ion permeability of the ryanodine receptor, a calcium releasing channel of sarcoplasmic reticulum. The cardiac ryanodine receptor, purified from pig heart, was reconstituted to proteoliposomes and then incorporated into a planar bilayer membrane. A single channel activity with a conductance of 724 pS in 900/200 mM (cis/trans) KCl and an ion selectivity of P-K:P-CI = 1:0.08 was observed. These characteristics are similar to those observed by the incorporation of the channel through sarcoplasmic reticulum vesicles. Hydroxyl radicals chemically generated by the reaction of H2O2 and Cu(ethylenediamine)(2) at the cis compartment increased the open probability of the channel. Treatment with SH oxidizing reagents from the cis compartment also increased the open probability, and dithiothreitol, a SH reducing agent, reversed the effect. These findings suggest that hydroxyl radicals react with some SH groups of the ryanodine receptor and increase the Ca2+ release from sarcoplasmic reticulum through the ryanodine receptor. (C) 1998 Academic Press.