17 Amino acids are precursors of many specialized biomolecules Radioisotope tracer experiments showed that the porphyrin(卟啉) ring of the heme groups in mammals are made from 8 Gly and 8 succinyl-CoA (Glu in plants and bacteria) Deficiency of enzymes leading to heme biosynthesis cause diseases called porphyrias (The degradation of heme yields bilirubin, a linear tetrapyrrole derivative, and the typical pigments found in bile, urine, and feces, a deficiency of which will cause jaundice,黄疸)
17. Amino acids are precursors of many specialized biomolecules • Radioisotope tracer experiments showed that the porphyrin (卟啉)ring of the heme groups in mammals are made from 8 Gly and 8 succinyl-CoA (Glu in plants and bacteria). • Deficiency of enzymes leading to heme biosynthesis cause diseases called porphyrias. • (The degradation of heme yields bilirubin, a linear tetrapyrrole derivative, and the typical pigments found in bile, urine, and feces, a deficiency of which will cause jaundice，黄疸)
Creatine, the energy buffer in skeletal muscle, is made from Gly, Arg, and Met Glutathione, the "redox buffer", is derived from Glu 's. and Gly Indole-3-acetate ( or auxin), the plant growth hormone, is derived from Trp Many important neurotransmitters, e.g., g aminobutyrate(GABA), serotonin(5 norepinephrine, epinephrine are derived from e ne. hydroxytryptamine,or5HI,5-羟色胺), dopa acids via simple pathways: all include a Plp amino depedent decarboxylation reaction
• Creatine, the “energy buffer” in skeletal muscle, is made from Gly, Arg, and Met. • Glutathione, the “redox buffer”, is derived from Glu, Cys, and Gly. • Indole-3-acetate (or auxin), the plant growth hormone, is derived from Trp. • Many important neurotransmitters, e.g., gaminobutyrate (GABA), serotonin (5- hydroxytrptamine, or 5-HT, 5-羟色胺), dopamine, norepinephrine, epinephrine are derived from amino acids via simple pathways: all include a PLPdepedent decarboxylation reaction
Polyamines(e.g, spermidine and spermine), needed for DNa packaging, is made from Met and ornithine Nitric oxide(NO), a stable free radical signals for vasodilation(血管舒张) in vertebrates, is made from the guanidino group of Arg and O, in a reaction catalyzed by an monooxygenase, nitric oxide synthase (NOs nos is a dimeric enzyme with each subunit containing an array of redox coenzymes: NADP FMN, FAD, tetrahydrobiopterin, and Fest-heme
• Polyamines (e.g., spermidine and spermine), needed for DNA packaging, is made from Met and ornithine. • Nitric oxide (NO), a stable free radical signals for vasodilation (血管舒张) in vertebrates, is made from the guanidino group of Arg and O2 in a reaction catalyzed by an monooxygenase, nitric oxide synthase (NOS). • NOS is a dimeric enzyme with each subunit containing an array of redox coenzymes: NADP, FMN, FAD, tetrahydrobiopterin, and Fe3+ -heme
COO Two molecules of 6-aminolevulinate CH2 Porphyrins Succinyl-COA C-S-CoA OoC CH%-Co0 IIn mammals are O CH, CH2 made from Gly Glycin COO CoA-SH m鬯来家 and succiny-CoA COo Four molecules of reactions I and 6 CH ③卜4NH occur in the mitochondria a-Amino-B C=0 ketoadipate the rest in the cytosols CH-NH s-aminolevulinate 4C02 COo synthase(main ⑥卜4CO2 ①CO2 control target for CH3 CH-CH COO heme biosynthesis) CH C=CH Ferrochelatase CH CHa-C-C C-CHa NH HN C=0 亚铁合 CH N C=C-CH=CHa tHeme CH, HC-C C-CH NHa F 8-Aminolevulinate δ-氨基—y-酮戊酸 CHo CH CH? Protoporphyrin IX 原卟
Porphyrins In mammals are made from Gly and succinyl-CoA (reactions 1 and 6 occur in the mitochondria, the rest in the cytosols) d-aminolevulinate synthase (main control target for heme biosynthesis) 胆色素原 原卟啉 d-氨基—g-酮戊酸 Heme Ferrochelatase 亚铁螯合酶 Fe2+
NH2 cOo creatine (酸),the“ energ. (CH2)3 CH-NH3 COO buffer in skeletal muscle. → Ornithine is derided from Gly, Arg, NH Gundinesetite and Met CH coo adoMet←[ Methionine adoHey NH C-NH2 N--CH, Creatine COo →ADP OeP-0 N--CHs CH Phosphocreatine
Creatine (肌酸), the “energy buffer” in skeletal muscle, is derivded from Gly, Arg, and Met