Metabolism of purines and pyrimidines - exercise -

1. Metabolism of purines and pyrimidines- exercise - Vladimíra Kvasnicová

2. Purine nucleotides • include an aromatic cycle in the structure • can contain either adenine or thymine • include N-glycosidic bond • are composed of a nucleoside bound to phosphoric acid by an anhydride bond

3. Purine nucleotides • include an aromatic cycle in the structure • can contain either adenine or thymine • include N-glycosidic bond • are composed of a nucleoside bound to phosphoric acid by an anhydride bond

4. PURINE BASES Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

5. ribonucleosidedeoxyribonucleoside N-glycosidic bond Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

6. ribonucleotidedeoxyribonucleotide ester bond Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

7. Pyrimidine nucleotides • include an imidazol ring in the structure • include thymidine- and cytidine monophosphate • contain an ester bond • can include 3 phosphate groups in their structure

8. Pyrimidine nucleotides • include an imidazol ring in the structure • include thymidine- and cytidine monophosphate • contain an ester bond • can include 3 phosphate groups in their structure

9. PYRIMIDINE BASES Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

10. ribonucleosidesdeoxyribonucleoside Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

11. Ribonucleotides * N-glycosidic bond * ester bond * anhydride bond Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

12. Purine and pyrimidine nucleotides can be used • as nucleoside triphosphates for nucleic acid synthesis • in energetic metabolism of cells • for activation of metabolic intermediates of saccharides and lipids • in enzymatic reactions: some coenzymes are nucleotides

13. Purine and pyrimidine nucleotides can be used • as nucleoside triphosphates for nucleic acid synthesis • in energetic metabolism of cells • for activation of metabolic intermediates of saccharides and lipids • in enzymatic reactions: some coenzymes are nucleotides

14. Synthesis of nucleotides • uses products of pentose cycle • includes phosphoribosyl diphosphate (PRDP = PRPP) as a substrate • needs derivatives of folic acid • proceeds in a cytoplasm only

15. Synthesis of nucleotides • uses products of pentose cycle • includes phosphoribosyl diphosphate (PRDP = PRPP) as a substrate • needs derivatives of folic acidH4 –folate (THF) • proceeds in a cytoplasm only

16. pentose cycle PRPP = PRDP Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

17. Synthesis of purine nucleotides • uses ammonia as a nitrogen donor • proceeds in a cytoplasm • can start from nucleosides produced by degradation of nucleic acids • includes uric acid as an intermediate

18. Synthesis of purine nucleotides • uses ammonia as a nitrogen donor • proceeds in a cytoplasm • can start from nucleosides produced by degradation of nucleic acids • includes uric acid as an intermediateuric acid is the end product of purine ring degradation

19. Synthesis of purine nucleotides CYTOPLASM Obrázek převzat z http://web.indstate.edu/thcme/mwking/nucleotide-metabolism.html (leden 2007)

20. IMP AMP GMP Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

21. Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

22. Synthesis of pyrimidine nucleotides • starts by the reaction: PRDP + glutamine • proceeds only in a cytoplasm of cells • includes orotic acid as an intermediate • includes inosine monophosphate as an intermediate

23. Synthesis of pyrimidine nucleotides • starts by the reaction: PRDP + glutamine • proceeds only in a cytoplasm of cells • includes orotic acid as an intermediate • includes inosine monophosphate as an intermediate

24. Synthesis of pyrimidine nucleotides CYTOPLASM mitochondrion Obrázek převzat z http://web.indstate.edu/thcme/mwking/nucleotide-metabolism.html (leden 2007)

25. Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

26. Synthesis of 2-deoxyribonucleotides enzyme: ribonucleotide reductase+ small protein „thioredoxin“ Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

27. Synthesis of thymidine monophosphate Obrázek je převzat z učebnice: Devlin, T. M. (editor): Textbook of Biochemistry with Clinical Correlations, 4th ed. Wiley‑Liss, Inc., New York, 1997. ISBN 0‑471‑15451‑2

28. In a regulation of nucleotide synthesis participate: • 5´-phosphoribosyl-1´-diphosphate (PRDP) • feed back inhibition • enzyme carbamoyl phosphate synthetase II(synthesis of pyrimidines) • enzyme xanthine oxidase(synthesis of purines)

29. In a regulation of nucleotide synthesis participate: • 5´-phosphoribosyl-1´-diphosphate (PRDP) • feed back inhibition • enzyme carbamoyl phosphate synthetase II(synthesis of pyrimidines) • enzyme xanthine oxidase(synthesis of purines) = enzyme of purine degradation

30. Regulation of nucleotide synthesis

31. In a degradation of purine nucleotides • ammonia is released • CO2 is produced • the enzyme xanthine oxidase participates • uric acid is produced as the end product

32. In a degradation of purine nucleotides • ammonia is released • CO2 is produced • the enzyme xanthine oxidase participates • uric acid is produced as the end product

33. Degradation of purines = „uric acid“

34. In a degradation of pyrimidine nucleotides • -amino acids are produced • the enzyme xanthine oxidase participates • orotic acid is formed • ammonia is produced

35. In a degradation of pyrimidine nucleotides • -amino acids are produced • the enzyme xanthine oxidase participates • orotic acid is formed • ammonia is produced

36. Degradation of pyrimidines

37. Principal differences between metabolism of purines and pyrimidines