Chemical modification of arginines by 2,3-butanedione and phenylglyoxal causes closure of the mitochondrial permeability transition pore
Chemical modification of arginines by 2,3-butanedione and phenylglyoxal causes closure of the mitochondrial permeability transition pore
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DOI：
10.1074/jbc.273.20.12669
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发表时间：
1998-05-15
影响因子：
4.8
通讯作者：
Bernardi, P
中科院分区：
文献类型：
--
作者：
Eriksson, O;Fontaine, E;Bernardi, P
我们研究了精氨酸残基在调节线粒体通透性转换孔（环孢菌素 A 敏感的内膜通道）中的作用。用精氨酸特异性化学试剂2,3-丁二酮或苯基乙二醛处理离体的大鼠肝线粒体，然后去除多余的游离试剂。经过这种处理后，线粒体正常积累 Ca2+，但在去极化后没有发生通透性转变，这种情况通常会触发通透性转变孔的打开。 2,3-丁二酮和苯基乙二醛的抑制与基质 pH 相关，表明相关精氨酸暴露于基质水相。 2,3-丁二酮的抑制作用被贝拉特增强，并且在其去除后被逆转，而苯乙二醛的抑制作用是不可逆的。尽管存在 0.5 mM Ca2+，但在 Ca2+ 超载诱导渗透性转变后，用 2,3-丁二酮或苯基乙二醛处理导致孔隙闭合。在完全有效抑制渗透性转变的浓度下，这些精氨酸试剂 (i) 对亲环蛋白 D 的异构酶活性没有影响，并且 (ii) 不影响 ATP 转位和水解的速率（通过在鱼藤酮存在下添加 ATP 时产生的膜电位来测量）。我们得出结论，与 2,3-丁二酮和苯基乙二醛的反应导致位于 的关键精氨酸残基的稳定化学修饰。内膜的基质侧，反过来又强烈有利于孔的闭合状态。
We have investigated the role of arginine residues in the regulation of the mitochondrial permeability transition pore, a cyclosporin A-sensitive inner membrane channel. Isolated rat liver mitochondria were treated with the arginine-specific chemical reagent 2,3-butanedione or phenylglyoxal, followed by removal of excess free reagent. After this treatment, mitochondria accumulated Ca2+ normally, but did not undergo permeability transition following depolarization, a condition that normally triggers opening of the permeability transition pore. Inhibition by 2,3-butanedione and phenylglyoxal correlated with matrix pH, suggesting that the relevant arginine(s) are exposed to the matrix aqueous phase. Inhibition by 2,3-butanedione was potentiated by berate and was reversed upon its removal, whereas inhibition by phenylglyoxal was irreversible. Treatment with 2,3-butanedione or phenylglyoxal after induction of the permeability transition by Ca2+ overload resulted in pore closure despite the presence of 0.5 mM Ca2+. At concentrations that were fully effective at inhibiting the permeability transition, these arginine reagents (i) had no effect on the isomerase activity of cyclophilin D and (ii) did not affect the rate of ATP translocation and hydrolysis, as measured by the production of a membrane potential upon ATP addition in the presence of rotenone, We conclude that reaction with 2,3-butanedione and phenylglyoxal results in a stable chemical modification of critical arginine residue(s) located on the matrix side of the inner membrane, which, in turn, strongly favors a closed state of the pore.