Prof Dr Mohammad Ibrahim Prof of Medical Biochemistry

Transcription

1 Amino Acids Metabolism ١

2 Alanine β- Alanine ٢

3 Alanine CH 3 Structure It is α-amino propionic p acid Nutrional Value It is non-essential amino acid Metabolic Fate It is glucogenic g amino acid CH COOH ٣

4 Biosynthesis Alanine 1. From pyruvic acid 2. From serine 3. From cysteine 4. From tyrosine 5. From tryptophan 6. From aspartic acid ٤

5 Biosynthesis Alanine Glutamic acid α ketoglutaric O CH 3 C COOH PLP Aminotransferase Pyruvic (ALT) (GPT) CH 3 CH COOH Alanine Glucose Serine Cysteine Aspartic Tyrosine Tryptophan 3 phospho glycerate Glycine Phenyl alanine Glycerol Hydroxy proline Threonine Choline ٥

6 Alanine Metabolic Fate 1. Incorporated in protein structure 2. Formation of Pyruvic acid 3. Synthesis of glucose 4. Glucose alanine cycle ٦

7 Alanine 2- Formation of pyruvic acid A- Transamination α ketoglutaric Glutamic acid PLP O CH 3 CH COOH Aminotransferase CH 3 C COOH (ALT) (GPT) B- Oxidative deamination CH 3 H 2 O FMN FM CH COOH NH 3 L amino acid oxidase CH 3 C COOH O ٧

8 Alanine 3- Glucose biosynthesis α ketoglutaric Glutamic acid Alanine PLP Aminotransferase Pyruvic acid Glucose ٨

9 Alanine 4- Glucose alanine cycle Liver Blood Muscle Glucose Glucose Glucose Pyruvic Pyruvic NADH.H + NAD Lactic Glutamic Glutamic α Ketoglutaric Alanine Alanine Alanine α Ketoglutaric ٩

10 Structure formula Biosynthesis β Alanine CH 3 CH COOH α Alanine CH 2 CH 2 COOH β Alanine 1. From Aspartic acid 2. From pyrimidine catabolism 3. From carnosine ١٠

11 β Alanine 1- Biocynthesis from aspartic acid COOH CH 2 CH COOH β Decarboxylation CO 2 α Decarboxylation Aspartic CO 2 CH 3 CH COOH α Alanine CH 2 CH 2 COOH β Alanine ١١

12 β Alanine 2-Bisynthesis from pyrimidine catabolism O N Deaminase N H NH 3 Cytosine O O HN N H Uracil 2H H 2 O C O NH CH2 CH 2 COOH β urido propionic H 2 O NH 3 CO 2 CH 2 CH 2 COOH β Alanine ١٢

13 β Alanine 3-Bisynthesis from carnosine HN CH 2 CH 2 C N NH O Carnosinase CH 2 CH 2 COOH CH 2 CH COOH H 2 O β Alanine + Carnosine CH 2 CH COOH HN N Histidine ١٣

14 Metabolic Fate β Alanine 1. Enters in the structure t of: pantothenic acid CoASH 2. Forms dipeptides with histidine: Carnosine Anserine 3. Catabolized to acetyl CoA ١٤

15 Biosynthesis of carnosine and anserine HN β Alanine ATP ADP+Pi CH 2 CH 2 COOH + H 2 O HN N CH 2 CH COOH N Histidine Carnosine CH 2 CH 2 C CH 2 CH 2 C O 2 2 CH 2 CH 2 NH CH O NH CH COOH COOH CH 3 N CH 3 N Ansirine ١٥

16 β Alanyl histidine dipeptides activate myosin ATPase, enhance copper uptake. buffer the ph of anaerobically contracting skeletal muscle. Hydrolysis of carnosine is catalyzed by carnosinase. Carnosinase deficiency is characterized by Carnosinosis Carnosinuria i Muscle spasticity ١٦

17 β Alanine β-alanine catabolism O Deamination O Decarboxylation CH 2 CH 2 COOH CH CH 2 COOH CH CH 3 B Alanine NH Malonic semialdehyde 3 CO 2 Acetaldehyde Oxidation Oxidation HOOC CH 2 Malonic acid CoA.SH Thiokinase H 2 O 2 COOH HOOC CH 2 CO-S.CoA Malonyl CoA CoA.SH CH 3 COOH Acetic acid Thiokinase H 2 O CH 3 CO-S.CoA Acetyl CoA ١٧

18 Non α amino acids 1. β Alaninie 2. β Aminoisobutyric acid 3. γ Aminobutyric acid (GABA) 4. δ Aminolevulinic acid ١٨

19 Non protein amino acids 1. β Alaninie 2. β Aminoisobutyric i i acid 3. γ Aminobutyric acid (GABA) 4. δ Aminolevulinic l acid 5. α Amino β ketoadepic acid 6. α Amino β ketobutyric acid 7. Ornithine 8. Citrulline ١٩