Molecular Characterization of Acyl-CoA Dehydrogenases

描述(申请人摘要)：酰基辅酶A脱氢酶(ACDs)是一种 一类与进化相关的酶家族，参与第一步的 B-脂肪酸的氧化和亮氨酸的中间代谢， 异亮氨酸和缬氨酸。这些酶的缺乏是导致 人类新陈代谢的遗传缺陷。这样做的长期目标是 项目一直在调查重要的结构/功能关系 ACD基因家族。我们的一般假设是，这些信息将 更好地了解患者的基因/表型相关性 这些酶的缺陷。在之前的资助期，我们已经做出了 在表征结构、酶性质和 异戊酰辅酶A脱氢酶(IVD)的生物发生及鉴定 异戊酸血症患者中存在大量IVD突变。具体目标为 这一更新应用包括目标1：WD催化剂的表征 功能；目标2：测定氨基酸残基和基序 IVD同种异构体的稳定化；以及目标3：阐明 ACDs与电子传递黄素蛋白的相互作用 这些酶的电子受体。指导的定点突变 将使用结构分析和分子建模来创建突变 酶，以及新的生物物理技术将被开发，这将促进 对这些性质的研究。这项工作将导致对这一问题的更完整的理解 ACD基因家族，并最终提高诊断和治疗的能力 治疗这些酶缺乏的患者。

DESCRIPTION (applicant's abstract): The acyl-CoA dehydrogenases (ACDs) are a family of evolutionarily related enzymes involved in the first step of the B-oxidation of fatty acids and in the intermediate metabolism of leucine, isoleucine and valine. Deficiencies of these enzymes are important causes of inherited defects of metabolism in humans. The long-range objective of this project has been to investigate important structure/function relationships in the ACD gene family. Our general hypothesis is that this information will afford a better understanding of genotype/phenotype correlations in patients with deficiencies of these enzymes. In previous funding periods, we have made significant strides in characterizing the structure, enzymatic properties, and biogenesis of isovaleryl-CoA dehydrogenase (IVD), as well as identifying numerous IVD mutations in patients with isovaleric acidemia. Specific aims for this renewal application include Aim 1: characterization of WD catalytic function; Aim 2: determination of amino acid residues and motifs important for stabilization of IVD homotetrainers; and Aim 3: elucidation of the mechanism of interaction of ACDs with electron transferring flavoprotein, the physiologic electron acceptor for these enzyme. Site specific mutagenesis directed by structural analysis and molecular modeling will be used to create mutant enzymes, and new biophysical techniques will be developed which will facilitate study of these properties. This work will lead to a more complete understanding of the ACD gene family, and ultimately, to an improved ability to diagnose and treat patients with deficiencies of these enzymes.