PathwayStep957 PathwayStep954 PathwayStep2424 PathwayStep2420 PathwayStep2417 PathwayStep2416 PathwayStep2415 PathwayStep2414 PathwayStep2413 PathwayStep2412 PathwayStep2411 PathwayStep2410 PathwayStep2419 PathwayStep2418 PathwayStep2404 PathwayStep2406 PathwayStep2405 PathwayStep2408 PathwayStep2407 PathwayStep2409 Amino acid synthesis and interconversion (transamination) Authored: 2003-04-29 00:00:00 Edited: D'Eustachio, P, 0000-00-00 00:00:00 GENE ONTOLOGYGO:0008652 Reactome Database ID Release 4370614 Reactome, http://www.reactome.org ReactomeREACT_238 These reactions mediate the synthesis of aspartate, asparagine, glutamate, and glutamine from ammonia and intermediates of glycolysis, and allow the utilization of the carbon atoms from these four amino acids for glucose synthesis under fasting conditions.<P>These reactions also provide a means to collect nitrogen, both as ammonia and as amino groups, and direct it towards urea synthesis. Transamination, the conversion of an amino acid to the corresponding alpha-keto acid coupled to the conversion of a molecule of alpha-ketoglutarate to glutamate, is the first step in the catabolism of most amino acids. Transamination reactions are freely reversible so they also provide a means to balance concentrations of various amino acids and alpha-keto (2-oxo) acids in the cytosol. Serine biosynthesis aspartate + alpha-ketoglutarate <=> oxaloacetate + glutamate [GOT1] oxaloacetate + glutamate <=> aspartate + alpha-ketoglutarate [GOT2] alanine + alpha-ketoglutarate <=> pyruvate + glutamate [GPT] pyruvate + glutamate <=> alanine + alpha-ketoglutarate [GPT] aspartate + alpha-ketoglutarate <=> oxaloacetate + glutamate [GOT2] oxaloacetate + glutamate <=> aspartate + alpha-ketoglutarate [GOT1] pyruvate + glutamate <=> alanine + alpha-ketoglutarate [GPT2] alanine + alpha-ketoglutarate <=> pyruvate + glutamate [GPT2] ornithine + alpha-ketoglutarate <=> glutamate + L-glutamate gamma-semialdehyde [OAT] glutamate + L-glutamate gamma-semialdehyde <=> ornithine + alpha-ketoglutarate [OAT] glutamate + ATP + NADPH + H+ => L-glutamate gamma-semialdehyde + NADP+ + ADP + orthophosphate [P5CS] L-glutamate gamma-semialdehyde <=> L-1-pyrroline-5-carboxylate L-1-pyrroline-5-carboxylate + NADPH + H+ => proline + NADP+ aspartate + glutamine + ATP <=> asparagine + glutamate + AMP + pyrophosphate [ASNS] alpha-ketoglutarate + NH4+ + NAD(P)H + H+ <=> glutamate + NAD(P)+ [GLUD1] glutamate + NH4+ + ATP => glutamine + ADP + orthophosphate [GLUL] glutamate + NAD(P)+ => alpha-ketoglutarate + NH4+ + NAD(P)H + H+ [GLUD1] glutamine + H2O => glutamate + NH4+ [GLS] glutamine + pyruvate => 2-oxoglutaramate + alanine