Structural biology of enzymes in fatty acid metabolism

描述（由申请人提供）：乙酰辅酶A（乙酰辅酶A）羧化酶（ACC）、丙酮酸羧化酶（PC）、肉毒碱酰基转移酶和AMP活化蛋白激酶（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关键作用。ACC催化乙酰辅酶A的生物素依赖性羧化以产生丙二酰辅酶A，并且对于长链脂肪酸的生物合成和氧化至关重要。ACC 2-/-小鼠具有升高的脂肪酸氧化和降低的体脂和体重，表明针对ACC 2的抑制剂可有效控制体重和肥胖。PC催化丙酮酸羧化生成草酰乙酸。它对于从组织中去除丙酮酸是至关重要的，草酰乙酸产物对于脂肪酸生成、脂肪酸生物合成和葡萄糖诱导的胰岛素分泌是重要的。PC缺乏与人类的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CoA之间的酰基交换。肉毒碱棕榈酰转移酶（CPTs）在？ACC 2的丙二酰辅酶A产物是CPT-I酶的有效抑制剂。CPT-Is中的缺陷与低酮血症、低血糖和其他疾病有关。AMPK是一种主要的代谢调节剂，控制细胞中的许多过程。其g亚基的突变与许多人类疾病有关，包括Wolff-Parkinson-白色（WPW）综合征。最近的肥胖流行病的发病产生了显着的新的利益，这些重要的代谢酶。在上一个资助期间，我们产生了大量的ACC和肉毒碱酰基转移酶的结构和生化数据，大大提高了我们对这些酶的理解。然而，许多重要的问题仍然没有答案，目前有足够的结构信息的PC和AMPK。为了填补这些空白，在我们的知识，我们建议继续ACC和肉毒碱酰基转移酶的生物化学，生物物理和结构的研究，以及启动PC和AMPK等研究。这项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：最近开始的肥胖流行病产生了显着的新的兴趣，脂肪酸和碳水化合物代谢。我们提出的研究将产生关于这些重要代谢酶的详细结构和生化信息，为设计和开发在临床上有效的新型抑制剂/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.