Post on 14-Jul-2015
A i A id M t b liA i A id M t b liAmino Acids MetabolismAmino Acids Metabolism
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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•• AlanineAlanine•• AlanineAlanine•• AlanineAlanine
•• ββ AlanineAlanine
•• AlanineAlanine
•• ββ AlanineAlanine•• ββ-- AlanineAlanine•• ββ-- AlanineAlanine
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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AlanineAlanineAlanineAlanine
CH3 CH COOHNH2
• It is α-amino propionic acidStructureStructure
CH3 CH COOH
p pNutrional ValueNutrional Value
• It is non-essential amino acid Metabolic FateMetabolic Fate
• It is glucogenic amino acidMetabolic FateMetabolic Fate
g g
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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AlanineAlanineAlanineAlanine
BiosynthesisBiosynthesis
1. From pyruvic acid
BiosynthesisBiosynthesis
2. From serine 3 From cysteine3. From cysteine4. From tyrosine 5. From tryptophan6. From aspartic acid6. From aspartic acid
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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AlanineAlanineBiosynthesisBiosynthesisBiosynthesisBiosynthesis
Glutamic acid α ketoglutaric
AminotransferaseAminotransferaseCH3 C COOH
OCH3 CH COOH
NH2PLP
AminotransferaseAminotransferase(ALT)(ALT)(GPT)(GPT)
Pyruvic Alanine
Glucose Serine Cysteine Tyrosine TryptophanAspartic
Glycine Phenyl alanine3 phosphoglycerate
ThreonineHydroxyproline
CholineGlycerol
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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AlanineAlanine
Metabolic FateMetabolic Fate1. Incorporated in protein structure 2 F m ti f P i id2. Formation of Pyruvic acid3. Synthesis of glucosey g4. Glucose alanine cycle
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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AlanineAlanine22-- Formation of pyruvic acidFormation of pyruvic acid22-- Formation of pyruvic acidFormation of pyruvic acid
A- Transamination
Glutamic acidα ketoglutaric
ONH2
AminotransferaseAminotransferase(ALT) (GPT)(ALT) (GPT)
CH3 C COOHO
CH3 CH COOHNH2 PLP
(ALT) (GPT)(ALT) (GPT)
B- Oxidative deamination
NH3H2O
ONH2
FMN FMNH2
L amino acid oxidaseL amino acid oxidase CH3 C COOHCH3 CH COOH
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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AlanineAlanineAlanineAlanine33-- Glucose biosynthesisGlucose biosynthesis
Glutamic acidα ketoglutaric
Pyruvic acidAlanine
Glutamic acidg
PLP
AminotransferaseAminotransferase
GlucoseGlucose
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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AlanineAlanine44 Glucose alanine cycleGlucose alanine cycle44-- Glucose alanine cycleGlucose alanine cycle
LiverLiver BloodBlood MuscleMuscle
Glucose GlucoseGlucose
LiverLiver BloodBlood MuscleMuscle
PyruvicPyruvicNADH.H+ NAD
LacticPyruvicPyruvic Lactic
GlutamicGlutamic
α Ketoglutaricα Ketoglutaric
AlanineAlanineAlanineg
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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ββ AlanineAlanineStructure formulaStructure formula NHStructure formulaStructure formula
CH3 CH COOHNH2
CH2 CH2 COOHNH2
β Alanineα Alanine
BiosynthesisBiosynthesis
β Alanineα Alanine
yy
1. From Aspartic acid p2. From pyrimidine catabolism3. From carnosine
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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ββ AlanineAlanine11-- Biocynthesis from aspartic acidBiocynthesis from aspartic acid
COOHββ DecarboxylationDecarboxylation
CH CH COOHNH2
COOHCH2CH NH
CH3 CH COOH
α AlanineCO2
CHCOOH
NH2αα DecarboxylationDecarboxylation
CH2 CH2 COOHNH2
β AlanineAspartic CO2
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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ββ AlanineAlanine22 Bisynthesis from pyrimidine catabolismBisynthesis from pyrimidine catabolism22--Bisynthesis from pyrimidine catabolismBisynthesis from pyrimidine catabolism
NH2 ONH
N
NO
HN
NO β urido propionic
NH2C
NHO CH2 CH2 COOHDeaminase
NH
O
Cytosine
NH
O β urido propionicNH3 H2O2H
H2OUracil
NH3
NH2
CO2
CH2 CH2 COOHβ Alanine
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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ββ AlanineAlanine33 Bisynthesis from carnosineBisynthesis from carnosine33--Bisynthesis from carnosineBisynthesis from carnosine
NH
CH2 CH2 COOHNH2Carnosinase
NHCH2 CH2 CNH2
O
β AlanineH2OHN N
CH COOHCH2
+NH2
CH COOHCH2CarnosineHN N
Histidine
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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ββ AlanineAlanineMetabolic FateMetabolic Fate1 E t i th t t f1. Enters in the structure of:
• pantothenic acidp• CoASH
2 Forms dipeptides with histidine:2. Forms dipeptides with histidine:• Carnosine• Anserine
3 Catabolized to acetyl CoA3. Catabolized to acetyl CoA
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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Biosynthesis of carnosine and anserineBiosynthesis of carnosine and anserineyy
CH CH CNH2
Oβ Alanine
CH2 CH2 COOHNH2 NH
CH COOHCH2
CH2 CH2 C Oβ AlanineADP+PiATP
HN N
NH2
CH COOHCH2HN N+ H2O
CarnosineCH3
HN N
CH2 CH2 CNH2
O
HistidineCarnosine
NH
CH COOHCH2
2 2
N N
CH3
Ansirine
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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ββ Alanyl histidine dipeptidesAlanyl histidine dipeptides
• activate myosin ATPase,
ββ yy
• enhance copper uptake.
• buffer the pH of anaerobically contracting skeletal muscle.
• Hydrolysis of carnosine is catalyzed by carnosinase Hydrolysis of carnosine is catalyzed by carnosinase.
• Carnosinase deficiency is characterized by
– Carnosinosis
C i i– Carnosinuria
– Muscle spasticity
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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ββ AlanineAlanineββ Alanine catabolismAlanine catabolismββ--Alanine catabolismAlanine catabolism
NH2 O OD i iD i iCH2 CH2 COOH CH CH2 COOHO
CH CH3
O
CO2NH3B Alanine Malonic semialdehyde Acetaldehyde
DecarboxylationDecarboxylationDeaminationDeamination
OxidationOxidationOxidationOxidation
COOHCH3COOHCH2HOOCMalonic acid Acetic acid
ThiokinaseThiokinaseCoA.SH
H2O
CoA.SH
H2OThiokinaseThiokinase
CO-S.CoACH3CO-S.CoACH2HOOCMalonyl CoA Acetyl CoA
2
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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y
Non Non αα amino acidsamino acids
1.1. ββ Alaninie Alaninie 2.2. ββ Aminoisobutyric acidAminoisobutyric acid33 γγ Aminobutyric acid (GABA) Aminobutyric acid (GABA) 3.3. γγ Aminobutyric acid (GABA) Aminobutyric acid (GABA) 4.4. δδ Aminolevulinic acidAminolevulinic acid
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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Non protein amino acidsNon protein amino acids
1.1. ββ AlaninieAlaninie22 ββ A i i b t iA i i b t i idid2.2. ββ AminoisobutyricAminoisobutyric acidacid3.3. γγ AminobutyricAminobutyric acid (GABA) acid (GABA)
l ll l dd4.4. δδ AminolevulinicAminolevulinic acidacid5.5. αα Amino Amino ββ ketoadepicketoadepic acid acid 6.6. αα Amino Amino ββ ketobutyricketobutyric acidacid7.7. OrnithineOrnithine8.8. CitrullineCitrulline
Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry http://osp.mans.edu.eg/medbiochem_mi
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