protein turnover catabolism of amino acids ii

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Protein turnover Catabolism of amino acids II István Léránt

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Protein turnover Catabolism of amino acids II. István Léránt. CATABOLISM OF AMINO ACIDS ‚C’. Pyruvate Acetyl-CoA Acetoacetyl-CoA Alpha-ketoglutarate Succunyl-CoA Fumarate Oxalacetate. CATABOLISM OF AMINO ACIDS ‚C’. Ketoplastic amino acids Acetyl-CoA Acetoacetyl -CoA - PowerPoint PPT Presentation

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Page 1: Protein  turnover Catabolism  of  amino acids  II

Protein turnoverCatabolism of amino acids II

István Léránt

Page 2: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 2

CATABOLISM OF AMINO ACIDS ‚C’

PyruvateAcetyl-CoAAcetoacetyl-CoAAlpha-ketoglutarateSuccunyl-CoAFumarateOxalacetate

Page 3: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 3

CATABOLISM OF AMINO ACIDS ‚C’

• Ketoplastic amino acids– Acetyl-CoA– Acetoacetyl-CoA

• Glucoplastic amino acids– Pyruvate– Alpha-ketoglutarate– Succinyl-CoA– Fumarate– Oxalacetate

• Gluco- and ketoplastic amino acids

PyruvateAcetyl-CoAAcetoacetyl-CoAAlpha-ketoglutarateSuccunyl-CoAFumarateOxalacetate

Page 4: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 4

Formation of amphibolic intermediers

Glucoplastic Ketoplastic Gluco- and ketoplastic

Ala, Arg, Asp, Cys, Glu, Gly, His, Hyp, Met, Pro,

Ser, Thr,Val

Leu Ile, Lys, Phe, Trp, Tyr

Page 5: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 5

Page 6: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 6

CATABOLISM OF AMINO ACIDS ‚C’

Degradation of AlaSerCysThrresults in pyruvate formation

glutamate piruvate ateketoglutar- alanine ALAT

-232

4edehydratas serine

SCN;SO S;HCystein

NHpyruvate serine

Page 7: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 7

Carbon skeleton is degraded to pyruvate

L-Treonine

L-Glycine

L-Serine

Pyruvate

Acetil-KoA

L-Alanine L-Cysteine

Cystine

Pyruvate-dehydrogenase

CO2 + NH4+

Page 8: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 8

Page 9: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 9

CATABOLISM OF AMINO ACIDS ‚C’Degradation ofAspAsnResults in oxaloacetate

NH3+

COO-

OH

O

-OOC

O

COO- NH3+

COO- -OOC

OCOO-

OH O

+ +

L-aszpartát -ketoglutarát L-glutamát oxálacetát

NH3+

COO-

NH2

O

NH3+

COO-

OHO

OH2 NH3+

L-asparagine L-aspartate

+

L-aspartate -ketoglutarate L-glutamate oxaloacetate

Page 10: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 10

Page 11: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 11

CATABOLISM OF AMINO ACIDS ‚C’Degradation ofGlnGluProArgHisResults in formation of -ketoglutarate

Page 12: Protein  turnover Catabolism  of  amino acids  II

12

CATABOLISM OF AMINO ACIDS ‚C’Degradation ofGlnGluProArgHisresults in -ketoglutarate

His – precurcorHistamine (biogen amine)Carnosine (dipeptide, brain, muscle)

Protein turnover. Catabolism of amino acids

Page 13: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 13

CATABOLISM OF AMINO ACIDS ‚C’Degradation ofGlnGluProArgHisresults in -ketoglutarate

His – precurcorHistamine (biogen amine)Carnosine (dipeptide, brain, muscle) Histidinaemia, histidinuria

Histidase deficiency[histamine] á, [imidazole] á In blood, urine, cerebrospinal fluidDecreased [urocanic acid]

Rare, autosomal recessiveAsymptomatic, later hyperactivity, impeded speach

Page 14: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 14

CATABOLISM OF AMINO ACIDS ‚C’Degradation ofGlnGluProArgHisresults in -ketoglutarate

His – precursor of HistamineHistamine (biogen amine)Carnosine (dipeptide, brain, muscle)

Folic acidLaboratory test in folic acid deficiencyFiglu (Form-imino-glutamate) á

Page 15: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 15

CATABOLISM OF AMINO ACIDS ‚C’Degradation ofGlnGluProArgHisresults in -ketoglutarate

Page 16: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 16

CATABOLISM OF AMINO ACIDS ‚C’Degradation ofGlnGluProArgHisresults in -ketoglutarate

Proline oxydase, pyrroline-5-carboxylate dehydrogenase

Hyperprolinaemia I Hyperprolinaemia I: prolin-dehydrogenase (Hz –symptoms of hyperprolinaemia)

Hyperprolinaemia IIHyperprolinaemia II: Glutamate-gsemialdehyd dehydrogenase (hyperhydroxypolinaemia, Hz absence of symptoms of hyperprolinaemia),

Page 17: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 17

Page 18: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 18

CATABOLISM OF AMINO ACIDS ‚C’Catabolism results in formation of succinyl-CoA

MetValIle

ß-oxidation of fatty acids of odd-numbered chainCholesterol – bile acids

Biotin Vit B12

Page 19: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 19

CATABOLISM OF AMINO ACIDS ‚C’Catabolism results in formation of succinyl-CoA

MetValIle

-ketobutyrate

Propionyl-CoA

Methylmalonyl-CoA

Succinyl-CoA

Met

Val

Leu

Page 20: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 20

CATABOLISM OF AMINO ACIDS ‚C’Catabolism results in formation of succinyl-CoA

MetValIle

Page 21: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 21

CATABOLISM OF AMINO ACIDS ‚C’

• Hyperhomocysteinemia / hyperhomocysteinaemia [homocysteine] blood áá

– Pyridoxine / (B6)– folic acid (B9)

– Vitamin B12

• Deficiency of • methylentetrahydrofolate

reductase methioninsynthetase • Risk factor for recurrent venous

thrombosis

MetValIle

Page 22: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 22

CATABOLISM OF AMINO ACIDS ‚C’

-ketoacid-dehydrogenase

Leu Val Ile

Transaminase activity

-ketoacid derivative

CO2 + Acyl-CoA tioester

,ß-unsaturated acyl-CoA thioester

ß-Hydroxymethyl-Glutaryl-CoA

LeuSuccinyl-CoA

Val

Propionyl-CoA+ Acetyl-CoaIle

Page 23: Protein  turnover Catabolism  of  amino acids  II

Protein turnover. Catabolism of amino acids 23

CATABOLISM OF AMINO ACIDS ‚C’

Branched alpha-keto acid dehydrogenase multienzym complex

Alpha-ketoglutarate dehydrogenase

PDH

(Maple Syrup Urine Disease)

Methylmalonic aciduria

Propionic acidemia

PDH