Structural biology of enzymes in fatty acid metabolism

描述（由申请人提供）：乙酰辅酶A （acetyl-CoA）羧化酶（ACCs）、丙酮酸羧化酶（PC）、肉碱酰基转移酶和amp激活的蛋白激酶（AMPK）在脂肪酸和/或碳水化合物的代谢以及其他重要的细胞过程中起着至关重要的作用。ACCs催化生物素依赖性乙酰辅酶a羧化生成丙二酰辅酶a，对长链脂肪酸的生物合成和氧化至关重要。ACC2-/-小鼠的脂肪酸氧化升高，体脂和体重降低，提示抗ACC2抑制剂可能有效控制体重和肥胖。PC催化丙酮酸羧化反应生成草酰乙酸。它对于从组织中清除丙酮酸至关重要，草酰乙酸产物对于糖异生、脂肪酸生物合成和葡萄糖诱导的胰岛素分泌至关重要。PC缺乏与人类乳酸酸中毒和智力迟钝有关。肉毒碱酰基转移酶催化肉毒碱和辅酶a之间酰基的交换。肉毒碱棕榈酰基转移酶（CPTs）在？线粒体中脂肪酸的氧化，ACC2的丙二酰辅酶a产物是CPT-I酶的有效抑制剂。缺乏cpt - i与低酮血症、低血糖和其他疾病有关。AMPK是一种主要的代谢调节剂，控制着细胞中的许多过程。其g亚基的突变与包括沃尔夫-帕金森-怀特综合征在内的许多人类疾病有关。最近肥胖症的流行引起了人们对这些重要代谢酶的重新关注。在之前的资助期间，我们制作了大量关于ACC和肉毒碱酰基转移酶的结构和生化数据，大大增强了我们对这些酶的了解。然而，许多重要的问题仍未得到解答，目前关于PC和AMPK的结构信息不足。为了填补这些知识空白，我们建议继续进行ACC和肉毒碱酰基转移酶的生化、生物物理和结构研究，并启动PC和AMPK的研究。该研究将为这些酶的机制和调控提供重要的新见解，并为其抑制剂或激动剂的设计和开发提供基础。公共卫生相关性：最近肥胖症的流行引起了对脂肪酸和碳水化合物代谢的重新关注。我们提出的研究将提供这些重要代谢酶的详细结构和生化信息，为设计和开发临床有效的新型抑制剂/激动剂奠定基础。

DESCRIPTION (provided by applicant): Acetyl-coenzyme A (acetyl-CoA) carboxylases (ACCs), pyruvate carboxylase (PC), carnitine acyltransferases, and AMP-activated protein kinase (AMPK) play crucial roles in the metabolism of fatty acids and/or carbohydrates, as well as other important cellular processes. ACCs catalyze the biotin-dependent carboxylation of acetyl-CoA to produce malonyl-CoA, and are crucial for the biosynthesis and oxidation of long-chain fatty acids. ACC2-/- mice have elevated fatty acid oxidation and reduced body fat and body weight, suggesting that an inhibitor against ACC2 may be efficacious in the control of body weight and obesity. PC catalyzes the carboxylation of pyruvate to produce oxaloacetate. It is crucial for removing pyruvate from tissues, and the oxaloacetate product is important for gluconeogenesis, fatty acid biosynthesis, and glucose-induced insulin secretion. PC deficiency is linked to lactic acidosis and mental retardation in humans. Carnitine acyltransferases catalyze the exchange of acyl groups between carnitine and CoA. The carnitine palmitoyltransferases (CPTs) have crucial roles in the ?-oxidation of fatty acids in the mitochondria, and the malonyl-CoA product of ACC2 is a potent inhibitor of the CPT-I enzymes. Deficiencies in CPT-Is are linked to hypoketonemia, hypoglycemia and other diseases. AMPK is a master metabolic regulator and controls many processes in the cell. Mutations in its g subunit have been linked to many human diseases including Wolff-Parkinson-White (WPW) syndrome. The recent onset of the obesity epidemic has generated significant renewed interests in these important metabolic enzymes. During the previous funding period, we produced a large amount of structural and biochemical data on ACC and the carnitine acyltransferases that have greatly enhanced our understanding of these enzymes. However, many significant questions remain unanswered, and currently there is insufficient structural information on PC and AMPK. To fill these gaps in our knowledge, we propose to continue the biochemical, biophysical and structural studies on ACC and carnitine acyltransferases, as well as initiate such studies on PC and AMPK. The proposed research should provide significant new insights into the mechanism and regulation of these enzymes, and provide a foundation for the design and development of their inhibitors or agonists. PUBLIC HEALTH RELEVANCE: The recent onset of the obesity epidemic has generated significant renewed interests in fatty acid and carbohydrate metabolism. Our proposed research will produce detailed structural and biochemical information on these important metabolic enzymes, laying the foundation for the design and development of novel inhibitors/agonists that could be efficacious in the clinic.