1. Amino Acids M t b li
A i A id Metabolism
١ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

2. • Alanine
• β- Alanine
٢ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

3. Alanine
NH2
CH 3 CH COOH
Structure
• It is α-amino propionic acid
p p
Nutrional Value
• It is non-essential amino acid
Metabolic Fate
• It is glucogenic amino acid
g g
٣ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

4. Alanine
Biosynthesis
1. From pyruvic acid
2. From serine
3.
3 From cysteine
4. From tyrosine
5. From tryptophan
6. From aspartic acid
٤ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

5. Alanine
Biosynthesis
Glutamic acid α ketoglutaric
O NH2
CH 3 C COOH PLP CH 3 CH COOH
Aminotransferase
Pyruvic (ALT) Alanine
(GPT)
Glucose Serine Cysteine Aspartic Tyrosine Tryptophan
3 phospho
glycerate
Glycine Phenyl alanine
Hydroxy Threonine Choline
Glycerol proline
٥ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

6. Alanine
Metabolic Fate
1. Incorporated in protein structure
2.
2 Formation f Pyruvic acid
F m ti of P i id
3. Synthesis of glucose
y g
4. Glucose alanine cycle
٦ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

7. Alanine
2- Formation of pyruvic acid
A- Transamination
α ketoglutaric
Glutamic acid
NH2 PLP O
CH 3 CH COOH CH 3 C COOH
Aminotransferase
(ALT) (GPT)
B- Oxidative deamination
H2O FMN FMNH2 NH
3
NH2 O
CH 3 CH COOH CH 3 C COOH
L amino acid oxidase
٧ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

8. Alanine
3- Glucose biosynthesis
α ketoglutaric
g Glutamic acid
Alanine
PLP
Pyruvic acid
Aminotransferase
Glucose
٨ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

9. Alanine
4- Glucose alanine cycle
Liver Blood Muscle
Glucose Glucose Glucose
NADH.H+ NAD
Pyruvic Pyruvic Lactic
Glutamic Glutamic
α Ketoglutaric
α Ketoglutaric
g
Alanine Alanine Alanine
٩ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

10. β Alanine
Structure formula NH2 NH 2
CH 3 CH COOH CH 2 CH2 COOH
α Alanine β Alanine
Biosynthesis
y
1. From Aspartic acid
p
2. From pyrimidine catabolism
3. From carnosine
١٠ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

11. β Alanine
1- Biocynthesis from aspartic acid
NH2
β Decarboxylation
COOH CH 3 CH COOH
CH 2 CO2 α Alanine
CH NH 2
NH 2
COOH α Decarboxylation
CH 2 CH2 COOH
Aspartic CO2 β Alanine
١١ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

12. β Alanine
2-Bisynthesis from pyrimidine catabolism
NH 2 O
NH 2
N Deaminase HN C
O NH CH 2 CH 2 COOH
O N O N β urido propionic
H NH3 H 2H H2O
Cytosine Uracil H2O
NH3
CO2
NH 2
CH 2 CH2 COOH
β Alanine
١٢ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

13. β Alanine
3-Bisynthesis from carnosine
NH2
CH2 CH2 C O Carnosinase NH 2
NH CH 2 CH2 COOH
CH2 CH COOH H2O β Alanine
HN N
+
NH2
Carnosine CH2 CH COOH
HN N
Histidine
١٣ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

14. β Alanine
Metabolic Fate
1. Enters in the structure of:
1 E t i th t t f
• pantothenic acid
p
• CoASH
2.
2 Forms dipeptides with histidine:
• Carnosine
• Anserine
3.
3 Catabolized to acetyl CoA
١٤ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

15. Biosynthesis of carnosine and anserine
y
NH2
β Alanine
ATP ADP+Pi CH2 CH2 C O
NH 2 NH
CH 2 CH2 COOH CH2 CH COOH
+ NH2
H2O HN N
CH2 CH COOH
CH3
HN N Carnosine
Histidine NH2
CH2 CH2 C O
NH
CH2 CH COOH
N N Ansirine
CH 3
١٥ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

16. β Alanyl histidine dipeptides
y
• activate myosin ATPase,
• enhance copper uptake.
• buffer the pH of anaerobically contracting skeletal muscle.
• Hydrolysis of carnosine is catalyzed by carnosinase
carnosinase.
• Carnosinase deficiency is characterized by
– Carnosinosis
– C
Carnosinuria
i i
– Muscle spasticity
١٦ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

17. β Alanine
β-Alanine catabolism
NH 2 O O
Deamination
D i i Decarboxylation
CH 2 CH2 COOH CH CH2 COOH CH CH3
B Alanine NH3 Malonic semialdehyde CO Acetaldehyde
2
Oxidation Oxidation
HOOC CH 2 COOH CH 3 COOH
Malonic acid Acetic acid
CoA.SH
CoA.SH
Thiokinase Thiokinase
H2O H2O
HOOC CH 2 CO-S.CoA CH 3 CO-S.CoA
Malonyl CoA
y Acetyl CoA
١٧ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

18. Non α amino acids
1. β Alaninie
2. β Aminoisobutyric acid
3.
3 γ Aminobutyric acid (GABA)
4. δ Aminolevulinic acid
١٨ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi

19. Non protein amino acids
1. β Alaninie
2.
2 β A i i b t i acid
Aminoisobutyric id
3. γ Aminobutyric acid (GABA)
4. δ Aminolevulinic acid
l l d
5. α Amino β ketoadepic acid
6. α Amino β ketobutyric acid
7. Ornithine
8. Citrulline
١٩ Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry
http://osp.mans.edu.eg/medbiochem_mi