tailieunhanh - Inborn Metabolic Diseases Diagnosis and Treatment - part 4

Pyruvate được hình thành từ glucose và các monosacarit khác, từ lactate, và từ alanine amino axit gluconeogenic (Hình .). Sau khi nhập vào ty thể, pyruvate có thể được chuyển đổi thành acetylcoenzyme A (acetyl-CoA) pyruvate dehydrogenase phức tạp, theo sau bởi quá trình oxy hóa hơn nữa trong các TCA | 12 Disorders of Pyruvate Metabolism and the Tricarboxylic Acid Cycle Linda J. De Meirleir Rudy Van Coster Willy Lissens Pyruvate Carboxylase Deficiency - 163 Phosphoenolpyruvate Carboxykinase Deficiency - 165 Pyruvate Dehydrogenase Complex Deficiency - 167 Dihydrolipoamide Dehydrogenase Deficiency - 169 2-Ketoglutarate Dehydrogenase Complex Deficiency - 169 Fumarase Deficiency - 170 Succinate Dehydrogenase Deficiency - 171 Pyruvate Transporter Defect - 172 References - 172 162 Chapter 12 Disorders of Pyruvate Metabolism and the Tricarboxylic Acid Cycle Pyruvate Metabolism and the Tricarboxylic Acid Cycle Pyruvate is formed from glucose and other monosaccharides from lactate and from the gluconeogenic amino acid alanine o Fig . After entering the mitochondrion pyruvate can be converted into acetylcoenzyme A acetyl-CoA by the pyruvate dehydrogenase complex followed by further oxidation in the TCA cycle. Pyruvate can also enter the gluconeogenic pathway by sequential conversion into oxaloacetate by pyruvate carboxylase followed by conversion into phospho enolpyruvate by phosphoenolpyruvate carboxykinase. Acetyl-CoA can also be formed by fatty acid oxidation or used for lipogenesis. Other amino acids enter the TCA cycle at several points. One of the primary functions of the TCA cycle is to generate reducing equivalents in the form of reduced nicotinamide adenine dinucleotide and reduced flavin adenine dinucleotide which are utilized to produce energy under the form of ATP in the electron transport chain. o Fig. . Overview of glucose pyruvate lactate fatty acid and amino acid oxidation by the tricarboxylic acid cycle. A aconitase CS citrate synthase F fumarase ID isocitrate dehydrogenase KDHC a-or 2-ketoglutarate dehydrogenase complex MD malate dehydrogenase PC pyruvate carboxylase PDHC pyruvate dehydrogenase complex PEPCK phosphoenolpyruvate carboxykinase SD succinate dehydrogenase ST succinyl coenzyme A transferase. .