The 29.9 kDa subunit of mitochondrial complex I is involved in the enzyme active/de-active transitions.
The 29.9 kDa subunit of mitochondrial complex I is involved in the enzyme active/de-active transitions.
复制标题
线粒体复合物 I 的 29.9 kDa 亚基参与酶的活性/去活性转变。
DOI：
10.1016/j.jmb.2005.06.005
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Videira,Arnaldo
中科院分区：
文献类型：
--
作者：
Ushakova,AlexandraV;Duarte,Margarida;Vinogradov,AndreiD;Videira,Arnaldo
线粒体呼吸链复合体I经历了从活跃到失活形式的转变。我们研究了来自粗神经孢子虫野生型和一个缺乏29.9kDa核编码复合物I亚基的零突变体的亚线粒体颗粒中的这一现象。基于酶活性、遗传杂交和蔗糖梯度下线粒体蛋白的分析，我们发现突变体中组装了大约五分之一具有与野生型酶相似催化特性的复合物I。突变复合体I仍然表现出活跃/去活跃的转变，表明其他蛋白质参与了这种现象。然而，nuo29.9的配合物I活性/去活性转变的动力学特征与野生型不同。突变酶的自发失活要慢得多，这意味着29.9kDa的多肽参与了这一事件。我们认为真菌29.9kDa蛋白及其在其他生物中的同源物可能调节复合体I的活性/去活性转变。
Mitochondrial respiratory chain complex I undergoes transitions from active to de-activated forms. We have investigated the phenomenon in sub-mitochondrial particles from Neurospora crassa wild-type and a null-mutant lacking the 29.9kDa nuclear-coded subunit of complex I. Based on enzymatic activities, genetic crosses and analysis of mitochondrial proteins in sucrose gradients, we found that about one-fifth of complex I with catalytic properties similar to the wild-type enzyme is assembled in the mutant. Mutant complex I still displays active/de-active transitions, indicating that other proteins are involved in the phenomenon. However, the kinetic characteristics of complex I active/de-active transitions in nuo29.9 differ from wild-type. The spontaneous de-activation of the mutant enzyme is much slower, implicating the 29.9kDa polypeptide in this event. We suggest that the fungal 29.9kDa protein and its homologues in other organisms may modulate the active/de-active transitions of complex I.