人类二氢硫辛酰胺脱氢酶致病性突变体结构功能障碍的分子动力学研究及活性氧生成的调节。
Molecular dynamics study of the structural basis of dysfunction and the modulation of reactive oxygen species generation by pathogenic mutants of human dihydrolipoamide dehydrogenase.
机构信息
Department of Medical Biochemistry, Semmelweis University, Budapest 1094, Hungary.
出版信息
Arch Biochem Biophys. 2013 Oct 15;538(2):145-55. doi: 10.1016/j.abb.2013.08.015. Epub 2013 Sep 3.
Human dihydrolipoamide dehydrogenase (LADH, E3) is a component in the pyruvate-, alpha-ketoglutarate- and branched-chain ketoacid dehydrogenase complexes and in the glycine cleavage system. The pathogenic mutations of LADH cause severe metabolic disturbances, called E3 deficiency that often involve cardiological and neurological symptoms and premature death. Our laboratory has recently shown that some of the known pathogenic mutations augment the reactive oxygen species (ROS) generation capacity of LADH, which may contribute to the clinical presentations. A recent report concluded that elevated oxidative stress generated by the above mutants turns the lipoic acid cofactor on the E2 subunits dysfunctional. In the present contribution we generated by molecular dynamics (MD) simulation the conformation of LADH that is proposed to be compatible with ROS generation. We propose here for the first time the structural changes, which are likely to turn the physiological LADH conformation to its ROS-generating conformation. We also created nine of the pathogenic mutants of the ROS-generating conformation and again used MD simulation to detect structural changes that the mutations induced in this LADH conformation. We propose the structural changes that may lead to the modulation in ROS generation of LADH by the pathogenic mutations.
人二氢硫辛酰胺脱氢酶(LADH,E3)是丙酮酸、α-酮戊二酸和支链酮酸脱氢酶复合物以及甘氨酸裂解系统的一个组成部分。LADH 的致病突变导致严重的代谢紊乱,称为 E3 缺乏症,常涉及心脏和神经系统症状以及过早死亡。我们实验室最近表明,一些已知的致病突变增加了 LADH 的活性氧(ROS)生成能力,这可能有助于临床表型。最近的一份报告得出结论,上述突变产生的氧化应激升高使 E2 亚基上的硫辛酸辅因子失活。在本研究中,我们通过分子动力学(MD)模拟生成了与 ROS 生成兼容的 LADH 构象。我们首次提出了可能将生理 LADH 构象转变为 ROS 生成构象的结构变化。我们还创建了 9 种 ROS 生成构象的致病性突变体,并再次使用 MD 模拟来检测突变在这种 LADH 构象中诱导的结构变化。我们提出了可能导致致病性突变调节 LADH 的 ROS 生成的结构变化。