2. Protein turnover. Catabolism of aminoacids I István Léránt

3. PROTEIN TURNOVER & AMINO ACID CATABOLISM Proteins are degraded to amino acids Building blocks of proteins Synthesis of N-containing compounds – hormones – nucleotides – porphyrins – biogen amines Protein turnover. Catabolism of aminoacids I. 2

4. PROTEIN TURNOVER & AMINO ACID CATABOLISM OrgansGlycogenFatsProteins Liver 1.6801.8901.680 Skeletal muscle 5.0401890100.800 Adipose tissue 34056.7000170 Brain 3000 Blood 2501900 Energy reserves of human body (Joule) Protein turnover. Catabolism of aminoacids I. 3

5. PROTEIN TURNOVER & AMINO ACID CATABOLISM Kwashiorkor Protein – energy malnutrition Edema, anorexia, hepatomegaly Possible causes Shortage of proteins Energy Fe, Se, I, folic acid, Vitamin C, Vitamin E, glutathion, unsaturated fatty acids Marasmus Protein – energy malnutrition Edema, drastic loss of adipose tissue, dry skin Possible causes Shortage of Proteins Energy Protein turnover. Catabolism of aminoacids I. 4

6. PROTEIN TURNOVER & AMINO ACID METABOLISM Proteins (cell proteins + proteins of food) Aminoacids Degradation Protein synthesis Hem, nucleotides, biogen amines, neurotransmitters, peptides …. Removal of N Carbon atoms – as major metabolic intermediates Protein turnover. Catabolism of aminoacids I. 5

7. PROTEIN TURNOVER & AMINO ACID CATABOLISM Synthesis of aminoacids – Essential aminoacids – Semiessential aminoacids – Non-essential aminoacids – Ala, Asn, Asp, Cys, Gln, Glu – Gly, Pro, Ser, Tyr – Gla*, Hyl*, Hyp* – Arg Protein turnover. Catabolism of aminoacids I. 6

8. DIGESTION OF DIETARY PROTEINS Digestive enzymes of stomach and of intestine Serine proteases Zn-proteases Carboxyl-protease Dietary proteins are degraded to aminoacids Protein turnover. Catabolism of aminoacids I. 7

9. DIGESTION OF DIETARY PROTEINS Pepsin Carboxyl-peptidase pH 1-2 HCl - denaturation Baktericide effect Specificity - cutting Aromatic aminoacids Dicarbonic acids Gastric dysfunctions HCl  - ulcus HCl  - gastric cancer IF-Vit B 12 Aminoacid and nucletide metabolism Protein turnover. Catabolism of aminoacids I. 8 Mechanism of HCl secretion of stomach

10. Pancreas Trypsinogen Chymotrypsinogen  - Chymotrypsin Trypsin Enteropeptidase  - Chymotrypsin Trypsin inhibitor Inactive trypsin DIGESTION OF DIETARY PROTEINS Protein turnover. Catabolism of aminoacids I. 9

11. 1……………………………………………………………………..245 Chy motr y psinog e n 16…………………………………………..245 1…………..15 Tr y psin - Chymotrypsin Chymotrypsin 16…………………….146 149………245 1……….13 - Chymotrypsin Protein turnover. Catabolism of aminoacids I. 10

12. Endopeptidase activity Protein turnover. Catabolism of aminoacids I. 11

13. Exopeptidase activity Aminopeptidase Carboxypeptidase Protein turnover. Catabolism of aminoacids I. 12

14. DIGESTION OF DIETARY PROTEINS Synthesis, storage: – Zymogen form Exopeptidases – Aminopeptidases – carboxypeptidases Endpeptidases Stimulus – Activation – Limited proteolysis Amplification Inhibitor molecules Szabályozás Protein turnover. Catabolism of aminoacids I. 13

15. DIGESTION OF DIETARY PROTEINS. Primarily Na + dependent transport Diffusion directly to the lumen of vessels Absorption of aminoacids Aminoacids Di-, tripeptides – intestinal epithelium Release into the blood hepatocytes Extrahepatic tissues (skeletal muscle, brain, adipose tissue) Gln, branched chain (Val, Ile, Leu) Protein turnover. Catabolism of aminoacids I. 14

16. DEGRADATION OF CELLULAR PROTEINS Degradation of cell proteins Amino acids – Protein (re)synthesis – Energy Hydrolysis – extracellular – Intracellular Tissue proteinase – collagenase, – MMP (matrix metallo- proteases) – Some of cathepsins – elastase Proteinases Wound healing Bakterial invasion tumor-invasion Metastasis-formation Wound healing Degradation of proteins Tumorcells, bacteria Digestion of surrounding tissues Protein turnover. Catabolism of aminoacids I. 15

17. DEGRADATION OF CELLULAR PROTEINS Glycoproteins of blood plasma Proteins of intracellular compartiments – Lysosomes / cathepsins Intracellular proteolysis – Receptor-mediated endocytosis Hepatocytes - asialoglycoproteines – ATP dependent degradation of proteins Ubiquitin (UB) Protein turnover. Catabolism of aminoacids I. 16

18. DEGRADATION OF CELLULAR PROTEINS t 1/2 half-life Half-life – function Signalling Degradation: inhibition of accumulation and aggregation – Translation errors – Oxidative stress Protein aggregation Parkinson disease Huntington disease Protein turnover. Catabolism of aminoacids I. 17

19. DEGRADATION OF CELLULAR PROTEINS Structure and function of ubiquitin (UB) conservativ „extended” carboxy-terminus C terminal Gly of ubiquitin binds to  - amino group of protein to be degraded Isopeptid bound Lys48, The major site of linking additional ubiquitin molecules. Protein turnover. Catabolism of aminoacids I. 18

20. DEGRADATION OF CELLULAR PROTEINS Structure of a TETRAUBIQUITIN 4 ubiquitin Isopeptid bound „extended” C terminal carboxylat groups Lysine-  -amino-group Protein turnover. Catabolism of aminoacids I. 19

21. DEGRADATION OF CELLULAR PROTEINS E1 – ubiquitin-activating enzyme E2 – ubiquitin-conjugating enzyme E3 – ubiquitin-protein ligase Ubiquitin-activating enzyme Adenylation (1) Transfers the ubiquitin to one of its Cys-SH residues (2) Ubiquitin-conjugating enzyme Ubiquitin is bound by the Cys-SH of the ubiquitin-conjugating enzyme (3) Ubiquitin-protein ligase enzyme Transfers the ubiquitin to the  - aminoacid side chain residue of the target protein (4a és 4b) Tetra-ubiquitin Protein turnover. Catabolism of aminoacids I. 20

22. DEGRADATION OF CELLULAR PROTEINS 26 S proteasome Digestion of the ubiquitinated proteins 20 S catalytic unit (1) 19 S regulatory unit (2) Protein turnover. Catabolism of aminoacids I. 21

23. DEGRADATION OF CELLULAR PROTEINS The proteasome and other proteases generate free amino acids. Protein turnover. Catabolism of aminoacids I. 22

24. CATABOLISM OF AMINO ACIDS Amino acids Resynthesis of proteins, peptides Catabolism N – Urea cycle C - oxydation C – glucose and / or fatty acid Protein turnover. Catabolism of aminoacids I. 23

25. N CATABOLISM OF AMINO ACIDS N amino acids +   -ketoglutarate  -ketoacid + L-glutamate L-glutamate  NH 4 + Protein turnover. Catabolism of aminoacids I. 24

26. CATABOLISM OF AMINO ACIDS TRANSAMINASE ACTIVITY –  -amino acid   -ketoacid Aspartate aminotransferase Alanine aminotransferase N Biosynthesis of amino acids Catabolism of amino acids Biosynthesis of N- containing molecules Protein turnover. Catabolism of aminoacids I. 25 ASAT / GOT ALAT / GPT

27. N CATABOLISM OF AMINO ACIDS N Biosynthesis of amino acids Catabolism of amino acids Biosynthesis of N- containing molecules Protein turnover. Catabolism of aminoacids I. 26 Glutamate-dehydrogenase ATP, GTP ADP

28. CATABOLISM OF AMINO ACIDS N Biosynthesis of amino acids Catabolism of amino acids Biosynthesis of N- containing molecules Protein turnover. Catabolism of aminoacids I. 27

29. CATABOLIMS OF AMINO ACIDS Vitamin B 6 – Transaminases – Decarboxylation – Desamination – Racemization Vitamin B 6 - transaminase Protein turnover. Catabolism of aminoacids I. 28

30. N CATABOLISM OF AMINO ACIDS N Vitamin B 6 TRANSAMINASE ACTIVITY Protein turnover. Catabolism of aminoacids I. 29

31. CATABOLISM OF AMINO ACIDS VITAMIN B 6 Protein turnover. Catabolism of aminoacids I. 30

32. N AMINO ACIDS N VITAMIN B 6 Ser, Thr / dehydration Protein turnover. Catabolism of aminoacids I. 31

33. N CATABOLISM OF AMINO ACIDS N N – of extrahepatic origin Liver - transport Glucose alanine cycle Glutamine synthase Protein turnover. Catabolism of aminoacids I. 32

34. N CATABOLISM OF AMINO ACIDS N N – of extrahepatic origin Liver - transport Glucose alanine cycle Glutamine synthase Protein turnover. Catabolism of aminoacids I. 33

35. N CATABOLISM OF AMINO ACIDS N Ammonothelic group: – NH 3 Uricothelic group: uric acid Ureothelic group: urea Protein turnover. Catabolism of aminoacids I. 34

36. THE UREA (ornithine) CYCLUS NH 4 + Asp Protein turnover. Catabolism of aminoacids I. 35

37. THE UREA CYCLE Carbamoyl phosphate synthetase N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 36

38. THE UREA CYCLE Carbamoyl phosphate synthetase N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 37

39. THE UREA CYCLE Carbamoyl phosphate synthetase N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 38

40. THE UREA CYCLE Carbamoyl phosphate synthetase N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 39

41. THE UREA CYCLE Carbamoyl phosphate synthetase N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 40

42. THE UREA CYCLE Carbamoyl phosphate synthetase N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 41

43. THE UREA CYCLE Integration of the N metabolism The urea cycle, gluconeogenesis and transamination of oxaloacetate are linked by fumarate + Asp Protein turnover. Catabolism of aminoacids I. 42

44. THE UREA CYCLE INTEGRARATION OF N Metabolism The urea cycle, gluconeogenesis and transamination of oxaloacetate are linked by fumarate + Asp The Natural Way to Clean Your Clothes in ancient Rome The process for obtaining the urine was rather interesting in itself. The fuller would place urine vessels on street corners for people to publicly relieve themselves. When the vessels were full, they were then carried back to the fullonica. The urine was diluted with water and the clothes were soaked in the mixture. Part of the cleaning process also involved someone standing in the tub of urine and stomping on the clothes, similar to an agitator on modern washing machines. After the clothes were cleaned, they were rinsed again to get the urine stench out of them. Protein turnover. Catabolism of aminoacids I. 43

45. THE UREA CYCLE blood NH 4 +, hyperammonemia vomiting lethargy coma, Brain damage Enzyme deficiencies of urea cyclus Carbamoyl phosphate synthetase-1 N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 44

46. THE UREA CYCLE – N-Acetylglutamate-synthase – Mitochondrial compartment Enzyme deficiencies of urea cyclus Carbamoyl phosphate synthetase-1 N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 45

47. THE UREA CYCLE – Carbamoylphophate synthase-1 – Mitochondrial compartment – Carbamoylphophate synthase-2 / Pyrimidine biosynthesis – cytosol Enzyme deficiencies of urea cyclus Carbamoyl phosphate synthetase-1 N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 46

48. THE UREA CYCLE – Ornithine- transcarbamoylase – Mitochondrial compartment – Orotic acid! Orotic aciduria – A secondary consequence of ornithine-transcarbamoylase deficiency Enzyme deficiencies of urea cyclus Carbamoyl phosphate synthetase-1 N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 47

49. THE UREA CYCLE – Argininosuccinate- synthetase – CYTOSOL – Def. of Argininosuccinate- synthase – Citrullinemia – [Citrullin]  Enzyme deficiencies of urea cyclus Carbamoyl phosphate synthetase-1 N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 48

50. THE UREA CYCLE – Argininosuccinase – CYTOSOL – Def. of Argininosuccinase – Argininosuccinate aciduria – Citrullinemia – [Citrullin]  – [Arginino-succinate]  Enzyme deficiencies of urea cyclus Carbamoyl phosphate synthetase-1 N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 49

51. THE UREA CYCLE – Arginase – CYTOSOL – Deficiency of arginase – argininemia – [Arg]  Enzyme deficiencies of urea cyclus Carbamoyl phosphate synthetase-1 N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 50

52. THE UREA CYCLE – Carbamoyl-phosphate synthetase – Mitochondrial compartiment – N excretion – citrullin – arginino succinate – Accumulation of Gly – Accumulation of Gln – Low protein diet – +benzoate, phenylacetate Enzyme deficiencies of urea cyclus Carbamoyl phosphate synthetase-1 N-Acetylglutamate-synthase Ornitine transcarbamoylase Argininosuccinate-synthase Argininosuccinase Arginase Protein turnover. Catabolism of aminoacids I. 51

53. Treatment for deficiencies of carbamoyl-phosphate synthase and ornitine transcarbamoylase Benzoate Phenylacetate Protein turnover. Catabolism of aminoacids I. 52