1. Catabolism of N in proteins and aminoacids

2. Catabolism of proteins and aminoacids
Proteins of body
Protein synthesis
Degradation
Food
Aminoacids
Digestion of proteins
Hem, purin-,
Pirimidin-derivatives
Hormons, neurotranszmitters
Peptides,
Peptide-like substances
a-NH2 group
Carbon skeleton

3. Amino acids Building blocks of proteins Classification
Side chains
Proteinogen
Ornithine /citrulline
Post-translational modification

4. Amino acids
Isomerism
D-alanine
L-alanine

5. Amino acids In human nutrition Essential Non-essential
Ile, Leu, Lys, Met, Phe, Thr, Trp, Val
Non-essential
Ala, Asn, Asp, Cys*, Glu, Gln*, Gly, Pro, Ser*, Tyr*, Arg*, His*

6. Amino acids Trp – serotonin Gly – porphyrins, hem, Arg, nitric oxide
Ornithine, Met – polyamines
Asp, Gly, Glu - nucleotides

7. Catabolism of aminoacids
a-amino group (N of side chain residues)
Carbonic backbone

8. Products derived from a-amino groups
Ammonothelic group:
Uricothelic group : uric acid
Ureothelic group: urea

9. Excretion of N Forms: Fishes: ammonothelic (NH4+)
Birds: uricothelic (uric acid)
Terrestial animals: uricothelic / ureothelic (uric acid / urea)

10. Hyperammonemy Portal circulation – NH3 of bacterial origin
Systemic circulation of practically free of NH3
Ammonia intoxication:
Tremor, fustian, visions, coma,

11. Aminoacids

12. Steps of urea excretion
Transamination
Oxidative desamination of Glutamate
Transport of Ammonia
Urea-cyclus (Ornithin-cyclus)

13. Transamination

14. The role of Vitamin B6 in transamination

15. The role of Vitamin B6 in transamination

16. The role of Vitamin B6 in transamination

17. The role of Vitamin B6 in transamination

18. Transamination

19. Transamination ALAT, ASAT

20. Transamination of non a-aminogroups

21. Steps of urea excretion, transamination:
Specific enzymes for one pair of the substrats
No-transaminating aas: Lys, Thr, Pro, Hyp
Ornitin (d-aminocsoport): transamination
L-glutamate – amino group „acceptor”
L-glutamate: oxidative desamination

22. Excretion of urea. L-aminoacid oxidase in Liver and Kidney

23. Steps of Urea Excretion
Transamination
Oxidative desamination of glutamate
Transport of N
Urea cyclus

24. Role of glutamate-dehydrogenase in N excretion

25. Steps of Urea Excretion
Transamination
Oxidative desamination of glutamate
Transport of N
Urea cyclus

26. Urea excretion. A glutamine-synthase binds ammonia

27. The glucose alanin cyclus

28. Tissue cooperativity in the urea synthesis

29. Transamination and desamination of aminoacids

30. Sources of N for urea cyclus

31. The Urea-Krebs – bicyclus

32. Steps of Urea cyclus Carbamoylphosphate synthase I.
N-acetylglutamate synthase
Ornitin-transcarbamoylase
Argininosuccinate-synthase
Argininosuccinate-lyase
Arginase

33. Steps of Urea cyclus Carbamoylphosphate synthase I.
N-acetylglutamate synthase
Ornitin-transcarbamoylase
Argininosuccinate-synthase
Argininosuccinate-lyase
Arginase

34. Steps of Urea cyclus Carbamoylphosphate synthase I.
N-acetylglutamate synthase
Ornitin-transcarbamoylase
Argininosuccinate-synthase
Argininosuccinate-lyase
Arginase

35. Steps of Urea cyclus Carbamoylphosphate synthase I.
N-acetylglutamate synthase
Ornitin-transcarbamoylase
Argininosuccinate-synthase
Argininosuccinate-lyase
Arginase

36. Steps of Urea cyclus Carbamoylphosphate synthase I.
N-acetylglutamate synthase
Ornitin-transcarbamoylase
Argininosuccinate-synthase
Argininosuccinate-lyase
Arginase

37. Steps of Urea cyclus Carbamoylphosphate synthase I.
N-acetylglutamate synthase
Ornitin-transcarbamoylase
Argininosuccinate-synthase
Argininosuccinate-lyase
Arginase

38. Deficiencies / Urea cyclus
Hiperammonemy 1:
Carbamoylphosphate synthase I.
Hiperammonemy 2:
Ornithine transcarbamoylase
X-chromosome linked
Mother suffers in hyperammonemy, aversion of proteins [glutamin]
Citrullinemy:
Def. Of Argininosuccinate-synthase
[Argininosuccinate] / blood, urine
Manifestation at age 2, death
Argininosuccinate acidury
Argininosuccinate-lyase
Hyperamminemy
Arginase
[Arg] / blood, cerebrospinal fluid