Role of B6 phosphate in amino acid metabolism

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Vitamin B6- Phosphate- Chemistry, activation and role in amino acid metabolism

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Role of B6 phosphate in amino acid metabolism

  1. 1. Biochemistry For Medics www.namrata.co Accepted for publication in Biochemistry for medics In Student’s corner 1Biochemistry for medics- Namrata Chhabra
  2. 2. 2Biochemistry for medics- Namrata Chhabra
  3. 3.  Introduction to Vitamin B6  Structure of Vitamin B6  Activation of Vitamin B6  Role in Amino Acid Metabolism Overview of Seminar  General Amino Acid Reactions  Metabolism of Tryptophan  Metabolism of Methionine  Metabolism of Glycine 3Biochemistry for medics- Namrata Chhabra
  4. 4.  Introduction to Vitamin B6  Structure of Vitamin B6  Activation of Vitamin B6  Role in Amino Acid Metabolism Overview of Seminar  General Amino Acid Reactions  Metabolism of Tryptophan  Metabolism of Methionine  Metabolism of Glycine 4Biochemistry for medics- Namrata Chhabra
  5. 5. B-Complex Vitamins  Water Soluble Vitamins  Earlier thought of as being a Single Vitamin  Later found to be composed of EIGHT Chemically distinct Vitamins Vitamin B1 (Thiamine) Vitamin B2 (Riboflavin) Vitamin B3 (Niacin) Vitamin B5 (Pantothenic Acid) Vitamin B6 Vitamin B7 (Biotin) Vitamin B9 (Folic Acid) Vitamin B12 (Cobalamin) INTRODUCTIO N: 5Biochemistry for medics- Namrata Chhabra
  6. 6. B-Complex Vitamins  Water Soluble Vitamins  Earlier thought of as being a Single Vitamin  Later found to be composed of EIGHT Chemically distinct Vitamins Vitamin B1 (Thiamine) Vitamin B2 (Riboflavin) Vitamin B3 (Niacin) Vitamin B5 (Pantothenic Acid) Vitamin B6 Vitamin B7 (Biotin) Vitamin B9 (Folic Acid) Vitamin B12 (Cobalamin) Vitamin B6 INTRODUCTIO N: 6Biochemistry for medics- Namrata Chhabra
  7. 7. B-Complex Vitamins INTRODUCTIO N:  Water Soluble Vitamins  Earlier thought of as being a Single Vitamin  Later found to be composed of EIGHT Chemically distinct Vitamins Vitamin B1 (Thiamine) Vitamin B2 (Riboflavin) Vitamin B3 (Niacin) Vitamin B5 (Pantothenic Acid) Vitamin B6 Vitamin B7 (Biotin) Vitamin B9 (Folic Acid) Vitamin B12 (Cobalamin) Vitamin B6 7Biochemistry for medics- Namrata Chhabra
  8. 8. HISTOR Y: Introduction  Discovered in 1934  Hungarian physician, Paul György  Ability to cure Dermititis Acrodynia in Rats  Isolated in 1938  Polish nutritionist, Samuel Lepkovsky  Isolated from Rice Bran  Structure of Pyridoxine in 1939  Harris and Folkers  Structure of Pyridoxal and Pyridoxamine in 1945  American Biochemist, Esmond Snell 8Biochemistry for medics- Namrata Chhabra
  9. 9. GOOD SOURCES Sources of Vitamin B6  Vitamin B6 is ABUNDANTLY present in:  Royal Jelly of Bees  Yeast  Rice Polishing  Cereal Grains  Egg Yolk  Germinal portion of various Seeds MODERATE SOURCES  Vitamin B6 is MODERATELY present in:  Liver  Kidney  Muscle  Fish POOR SOURCES  Vitamin B6 is POORLY present in:  Milk 9Biochemistry for medics- Namrata Chhabra
  10. 10. Structure  Derivatives of Pyridine Ring Pyridine Ring 10Biochemistry for medics- Namrata Chhabra
  11. 11. Structure  Derivatives of Pyridine Ring Purine RingPyridoxine 2-Methly, 3-Hydroxy, 4,5-diHydroxyMethly Pyridine  Pyridoxine 11Biochemistry for medics- Namrata Chhabra
  12. 12. Structure  Pyridoxal Purine RingPyridoxal 12Biochemistry for medics- Namrata Chhabra
  13. 13. Structure  Pyridoxamine Purine RingPyridoxamine 13Biochemistry for medics- Namrata Chhabra
  14. 14. Structure  Derivatives of Pyridine  Pyridoxine  Also known as Pyridoxol  4th position contains a CH2OH group  Precursor from of Vitamin B6  Plant in origin Pyridoxine Pyridoxal Pyridoxamine  Pyridoxal  4th position contains a CHO group  Precursor from of Vitamin B6  Plant in origin  Pyridoxamine  4th position contains a CH2NH2 group  Precursor from of Vitamin B6  Plant in origin 14Biochemistry for medics- Namrata Chhabra
  15. 15. Structure  Biochemically active only when Phosphorylated  Phosphorylation is brought about by Kinase enzyme  Phosphorylation occurs at 5th Position Pyridoxine Pyridoxine-P (Phosphate) Kinase 15Biochemistry for medics- Namrata Chhabra
  16. 16. Structure  Pyridoxine  Also known as Pyridoxol  4th position contains a CH2OH group  Precursor from of Vitamin B6  Plant in origin  Pyridoxal  4th position contains a CHO group  Precursor from of Vitamin B6  Plant in origin  Pyridoxamine  4th position contains a CH2NH2 group  Precursor from of Vitamin B6  Plant in origin Pyridoxine Pyridoxal Pyridoxamine 16Biochemistry for medics- Namrata Chhabra
  17. 17. Structure Pyridoxine Pyridoxal Pyridoxamine Pyridoxine-P Pyridoxal-P Pyridoxamine-P Kinase Kinase Kinase 17Biochemistry for medics- Namrata Chhabra
  18. 18. Structure  Biochemically active only when Phosphorylated  Phosphorylation is brought about by Kinase enzyme  Phosphorylation occurs at 5th Position  In total, there are 6 isoforms of Vitamin B6: Pyridoxine Pyridoxine-P (Phosphate)  Pyridoxine  Pyridoxine-P  Pyridoxal  Pyridoxal-P  Pyridoxamine  Pyridoxamine-P 18Biochemistry for medics- Namrata Chhabra
  19. 19. Structure  Biochemically active only when Phosphorylated  Phosphorylation is brought about by Kinase enzyme  Phosphorylation occurs at 5th Position  In total, there are 6 isoforms of Vitamin B6:  Pyridoxine  Pyridoxine-P  Pyridoxal  Pyridoxal-P  Pyridoxamine  Pyridoxamine-P  Pyridoxic Acid  Excretory form of Vitamin B6  Oxidation at 4th position Pyridoxic Acid NOTE: Vitamin B6 can also be excreted in the UNCHARGED form as Pyridoxine or Pyridoxal 19Biochemistry for medics- Namrata Chhabra
  20. 20. Structure  Biochemically active only when Phosphorylated  Phosphorylation is brought about by Kinase enzyme  Phosphorylation occurs at 5th Position  In total, there are 6 isoforms of Vitamin B6:  Pyridoxine  Pyridoxine-P  Pyridoxal  Pyridoxal-P  Pyridoxamine  Pyridoxamine-P  Pyridoxic Acid  Excretory form of Vitamin B6  Oxidation at 4th position Pyridoxic Acid NOTE: Vitamin B6 can also be excreted in the UNCHARGED form as Pyridoxine or Pyridoxal 20Biochemistry for medics- Namrata Chhabra
  21. 21. Activation of Vitamin B6  Biologically active forms are: a) Pyridoxal-PO4 b) Pyridoxamine-PO4 Pyridoxine Pyridoxal Pyridoxal-P Dehydrogenase Pyridoxal Kinase H2 ATP ADP Zn2+ Mg2+ 21Biochemistry for medics- Namrata Chhabra
  22. 22. Role in Amino Acid Metabolism  Absorption is by either PASSIVE or ACTIVE mechanisms  Vitamin B6 is absorbed by ACTIVE TRANSPORT  Amino Acid Absorption 22Biochemistry for medics- Namrata Chhabra
  23. 23. Role in Amino Acid Metabolism  General Amino Acid Reactions Transamination Reactions  SGPT (Serum Glutamate Pyruvate Transaminase) Glutamate Pyruvate 23Biochemistry for medics- Namrata Chhabra
  24. 24. Role in Amino Acid Metabolism  General Amino Acid Reactions Transamination Reactions  SGPT (Serum Glutamate Pyruvate Transaminase) Glutamate Pyruvate 24Biochemistry for medics- Namrata Chhabra
  25. 25. Role in Amino Acid Metabolism  General Amino Acid Reactions Transamination Reactions  SGPT (Serum Glutamate Pyruvate Transaminase) Glutamate PyruvateAlanine α-keto Glutarate 25Biochemistry for medics- Namrata Chhabra
  26. 26. Role in Amino Acid Metabolism Pyridoxal-P Pyruvic Acid (Recipient α-keto acid) Glutamate (Donor α-amino acid) Mechanism of Reaction 26Biochemistry for medics- Namrata Chhabra
  27. 27. Role in Amino Acid Metabolism Pyridoxal-P Pyruvic Acid (Recipient α-keto acid) Glutamate (Donor α-amino acid) Mechanism of Reaction 27Biochemistry for medics- Namrata Chhabra
  28. 28. Pyridoxal-P Glutamate (Donor α-amino acid) Role in Amino Acid Metabolism Pyridoxal-P Pyruvic Acid (Recipient α-keto acid) Glutamate (Donor α-amino acid) α-keto Glutarate (New α-keto acid) Pyridoxamine-P Mechanism of Reaction 28Biochemistry for medics- Namrata Chhabra
  29. 29. Pyruvic Acid (Recipient α-keto acid) Role in Amino Acid Metabolism Pyridoxal-P Pyruvic Acid (Recipient α-keto acid) Glutamate (Donor α-amino acid) α-keto Glutarate (New α-keto acid) Pyridoxamine-P Alanine (New α-amino acid) Pyridoxal-P Mechanism of Reaction 29Biochemistry for medics- Namrata Chhabra
  30. 30. Role in Amino Acid Metabolism  General Amino Acid Reactions Transamination Reactions  SGPT (Serum Glutamate Pyruvate Transaminase) α-keto Glutarate (New α-keto acid) Alanine (New α-amino acid) Pyruvate (Recipient α-keto acid) Glutamate (Donor α-amino acid) SGPT B6-P + + 30Biochemistry for medics- Namrata Chhabra
  31. 31. Role in Amino Acid Metabolism  General Amino Acid Reactions Transamination Reactions  SGPT (Serum Glutamate Pyruvate Transaminase) α-keto Glutarate (New α-keto acid) Alanine (New α-amino acid) Pyruvate (Recipient α-keto acid) Glutamate (Donor α-amino acid) SGPT B6-P + + 31Biochemistry for medics- Namrata Chhabra
  32. 32. Role in Amino Acid Metabolism  General Amino Acid Reactions Transamination Reactions  SGPT (Serum Glutamate Pyruvate Transaminase) Pyruvate + Glutamate Alanine + α-keto Glutarate  SGOT (Serum Glutamate Oxaloacetate Transaminase) Oxaloacetate + Glutamate Aspartate + α-keto Glutarate CLINICAL SIGNIFICANCE  Synthesis of Non-Essential Amino Acids  Alanine  Aspartate  Recycling of Carbon Skeletons  Pyruvate  Oxaloacetate 32Biochemistry for medics- Namrata Chhabra
  33. 33. Role in Amino Acid Metabolism  General Amino Acid Reactions Transamination Reactions  SGPT (Serum Glutamate Pyruvate Transaminase) Pyruvate + Glutamate Alanine + α-keto Glutarate  SGOT (Serum Glutamate Oxaloacetate Transaminase) Oxaloacetate + Glutamate Aspartate + α-keto Glutarate CLINICAL SIGNIFICANCE  Synthesis of Non-Essential Amino Acids  Alanine  Aspartate  Recycling of Carbon Skeletons  Pyruvate  Oxaloacetate 33Biochemistry for medics- Namrata Chhabra
  34. 34. Role in Amino Acid Metabolism  General Amino Acid Reactions Deamination Reactions  Non-Oxidative Deamination Serine 34Biochemistry for medics- Namrata Chhabra
  35. 35. Role in Amino Acid Metabolism  General Amino Acid Reactions Deamination Reactions  Non-Oxidative Deamination Dehydrase H2O B6-P H2ONH3 Serine Imino Acid Pyruvate Imino Acid 35Biochemistry for medics- Namrata Chhabra
  36. 36. Role in Amino Acid Metabolism  General Amino Acid Reactions Deamination Reactions  Non-Oxidative Deamination Dehydrase H2O B6-P H2ONH3 Serine Imino Acid Pyruvate Imino Acid 36Biochemistry for medics- Namrata Chhabra
  37. 37. Role in Amino Acid Metabolism  General Amino Acid Reactions Deamination Reactions  Non-Oxidative Deamination  Serine Deamination  Cysteine Deamination Serine Cysteine Pyruvate Pyruvate Water Hydrogen Sulphide + + Dehydrase B6-P Desulfhydrase B6-P CLINICAL SIGNIFICANCE  Breakdown of excess amino acids in Liver  Contributes to NH3 formation in the body NH3 NH3 37Biochemistry for medics- Namrata Chhabra
  38. 38. Role in Amino Acid Metabolism  General Amino Acid Reactions Deamination Reactions  Non-Oxidative Deamination  Serine Deamination  Cysteine Deamination Serine Cysteine Pyruvate Pyruvate Water Hydrogen Sulphide + + Dehydrase B6-P Desulfhydrase B6-P CLINICAL SIGNIFICANCE  Breakdown of excess amino acids in Liver  Contributes to NH3 formation in the body NH3 NH3 38Biochemistry for medics- Namrata Chhabra
  39. 39. Role in Amino Acid Metabolism  General Amino Acid Reactions Interconversion of Amino Acids  Racemases  Conversion of L-amino Acids to D-Amino Acids  Conversion of D-Amino Acids to L-Amino Acids RACEMASE B6-P L-AlanineD-Alanine 39Biochemistry for medics- Namrata Chhabra
  40. 40. Role in Amino Acid Metabolism  General Amino Acid Reactions Interconversion of Amino Acids  Racemase  Conversion of L-amino Acids to D-Amino Acids  Conversion of D-Amino Acids to L-Amino Acids RACEMASE B6-P L-AlanineD-Alanine 40Biochemistry for medics- Namrata Chhabra
  41. 41. Role in Amino Acid Metabolism  General Amino Acid Reactions Decarboxylation Reactions  Removal of CO2 to produce AMINES Histidine 41Biochemistry for medics- Namrata Chhabra
  42. 42. Role in Amino Acid Metabolism  General Amino Acid Reactions Decarboxylation Reactions  Removal of CO2 to produce AMINES Decarboxylase B6-P CO2 Histidine 42Biochemistry for medics- Namrata Chhabra
  43. 43. Role in Amino Acid Metabolism  General Amino Acid Reactions Decarboxylation Reactions  Removal of CO2 to produce AMINES Decarboxylase B6-P CO2 HistamineHistidine 43Biochemistry for medics- Namrata Chhabra
  44. 44. Role in Amino Acid Metabolism  General Amino Acid Reactions Decarboxylation Reactions  Removal of CO2 to produce AMINES Decarboxylase B6-P CO2 HistamineHistidine 44Biochemistry for medics- Namrata Chhabra
  45. 45. Role in Amino Acid Metabolism  General Amino Acid Reactions Decarboxylation Reactions  Removal of CO2 to produce AMINES Histidine 5-OH Tryptophan Glutamic Acid Histamine 5-OH Tryptamine (Serotonin) γ-Amino Butyric Acid Decarboxylase B6-P CO2 Decarboxylase B6-P CO2 Decarboxylase B6-P CO2 45Biochemistry for medics- Namrata Chhabra
  46. 46.  Histamine  Synthesised by Basophils and Mast Cells  Mediator of Hypersensitivity Reactions  Triggers Inflammatory Reactions  Neurotransmitter in the Gut  γ-Amino Butyric Acid  Inhibitor Neurotransmitter in the CNS  GABA Deficiency produces a state of Hyper excitation  Convulsions  Precipitating factor for Epileptic Seizures  Serotonin  Neurotransmitter in CNS  Regulates Behaviour and Cognitive functions  Deficiency leads to Depression, Anxiety and Personality Disorders  Regulates Intestinal Motility in Gut Role in Amino Acid Metabolism CLINICAL SIGNIFICANCE 46Biochemistry for medics- Namrata Chhabra
  47. 47. Role in Amino Acid Metabolism  Tryptophan Metabolism Tryptophan Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid NIACIN Kynureninase B6-P 47Biochemistry for medics- Namrata Chhabra
  48. 48. Role in Amino Acid Metabolism  Tryptophan Metabolism Tryptophan Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid NIACIN Kynureninase B6-P CLINICAL SIGNIFICANCE  Pathway for Endogenous NIACIN synthesis  In Vitamin B6 deficiency  Niacin Deficiency  PELLAGRA sets in † Dermatitis 48Biochemistry for medics- Namrata Chhabra
  49. 49. Role in Amino Acid Metabolism  Tryptophan Metabolism Tryptophan Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid NIACIN Kynureninase B6-P CLINICAL SIGNIFICANCE  Pathway for Endogenous NIACIN synthesis  In Vitamin B6 deficiency  Niacin Deficiency  PELLAGRA sets in † Dermatitis 49Biochemistry for medics- Namrata Chhabra
  50. 50. Role in Amino Acid Metabolism  Tryptophan Metabolism Tryptophan Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid NIACIN Kynureninase B6-P CLINICAL SIGNIFICANCE  Pathway for Endogenous NIACIN synthesis  In Vitamin B6 deficiency  Niacin Deficiency  PELLAGRA sets in † Dermatitis † Dementia 50Biochemistry for medics- Namrata Chhabra
  51. 51. Role in Amino Acid Metabolism  Tryptophan Metabolism Tryptophan Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid NIACIN Kynureninase B6-P CLINICAL SIGNIFICANCE  Pathway for Endogenous NIACIN synthesis  In Vitamin B6 deficiency  Niacin Deficiency  PELLAGRA sets in † Dermatitis † Dementia † Diarrhoea 51Biochemistry for medics- Namrata Chhabra
  52. 52. Role in Amino Acid Metabolism  Tryptophan Metabolism Tryptophan Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid NIACIN Kynureninase B6-P CLINICAL SIGNIFICANCE  Pathway for Endogenous NIACIN synthesis  In Vitamin B6 deficiency  Niacin Deficiency  PELLAGRA sets in † Dermatitis † Dementia † Diarrhoea † DEATH 52Biochemistry for medics- Namrata Chhabra
  53. 53. Role in Amino Acid Metabolism  Tryptophan Metabolism Tryptophan Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid NIACIN Kynureninase B6-P CLINICAL SIGNIFICANCE  Pathway for Endogenous NIACIN synthesis  In Vitamin B6 deficiency  Niacin Deficiency  PELLAGRA sets in † Dermatitis † Dementia † Diarrhoea † DEATH  In ISONIAZID therapy for Tuberculosis Isoniazid + Isoniazid B6-P Hydrasone B6-P 53Biochemistry for medics- Namrata Chhabra
  54. 54. Role in Amino Acid Metabolism  Tryptophan Metabolism Tryptophan Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid NIACIN Kynureninase B6-P CLINICAL SIGNIFICANCE  Pathway for Endogenous NIACIN synthesis  In Vitamin B6 deficiency  Niacin Deficiency  PELLAGRA sets in † Dermatitis † Dementia † Diarrhoea † DEATH  In ISONIAZID therapy for Tuberculosis Isoniazid + Isoniazid B6-P Hydrasone B6-P B6-P 54Biochemistry for medics- Namrata Chhabra
  55. 55. Role in Amino Acid Metabolism  Tryptophan Metabolism Tryptophan NIACIN CLINICAL SIGNIFICANCE  Pathway for Endogenous NIACIN synthesis  In Vitamin B6 deficiency  In ISONIAZID therapy for Tuberculosis  Tryptophan Loading Test Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid Kynureninase B6-P Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid Kynureninase B6-P 55Biochemistry for medics- Namrata Chhabra
  56. 56. Role in Amino Acid Metabolism  Tryptophan Metabolism Tryptophan NIACIN CLINICAL SIGNIFICANCE  Pathway for Endogenous NIACIN synthesis  In Vitamin B6 deficiency  In ISONIAZID therapy for Tuberculosis  Tryptophan Loading Test Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid Kynureninase B6-P Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid Kynureninase B6-P Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid Kynureninase B6-P Xanthurenic Acid 56Biochemistry for medics- Namrata Chhabra
  57. 57. Role in Amino Acid Metabolism  Tryptophan Metabolism Tryptophan NIACIN CLINICAL SIGNIFICANCE  Pathway for Endogenous NIACIN synthesis  In Vitamin B6 deficiency  In ISONIAZID therapy for Tuberculosis  Tryptophan Loading Test Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid Kynureninase B6-P Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid Kynureninase B6-P Kynurenine 3-OH-Kynurenine 3-OH-Anthranilic Acid Kynureninase B6-P Xanthurenic Acid 57Biochemistry for medics- Namrata Chhabra
  58. 58. Role in Amino Acid Metabolism  Methionine Metabolism  Methionine metabolism occurs in 2 phases  Phase I - Conversion of Methionine to HOMOCYSTEINE  Phase II - Further metabolism of HOMOCYSTEINE Methionine HOMOCYSTEINE Serine+ Cystathionine CysteineHomoserine Cystathionine β SynthaseB6-P Cystathionine LyaseB6-P CLINICAL SIGNIFICANCE  Pathway for synthesis of Non-Essential Amino Acids like Cysteine  In Vitamin B6 deficiency  HOMOCYSTEINAEMIA  Homocysteine is Atherogenic  Ischaemic Heart Disease  Brain Stroke 58Biochemistry for medics- Namrata Chhabra
  59. 59. Role in Amino Acid Metabolism  Glycine Metabolism Glycine HydroxyMethly THF Interconversion of Glycine to Serine 59Biochemistry for medics- Namrata Chhabra
  60. 60. Serine Hydroxymethly Transferase B6-P Glycine Serine “Free” THF HydroxyMethly THF Role in Amino Acid Metabolism  Glycine Metabolism Interconversion of Glycine to Serine CLINICAL SIGNIFICANCE  Synthesis of Non-Essential Amino Acid Serine 60Biochemistry for medics- Namrata Chhabra
  61. 61. Serine Hydroxymethly Transferase B6-P Glycine Serine “Free” THF HydroxyMethly THF Role in Amino Acid Metabolism  Glycine Metabolism Interconversion of Glycine to Serine CLINICAL SIGNIFICANCE  Synthesis of Non-Essential Amino Acid Serine 61Biochemistry for medics- Namrata Chhabra
  62. 62. Tetra Hydro Folate B6-P GCS Glycine Role in Amino Acid Metabolism  Glycine Metabolism Glycine Cleavage System 62Biochemistry for medics- Namrata Chhabra
  63. 63. Tetra Hydro Folate + N5,10 Methylene Tetra Hydro Folate B6-P GCS Glycine Role in Amino Acid Metabolism  Glycine Metabolism Glycine Cleavage System Carbon Dioxide Ammonia 63Biochemistry for medics- Namrata Chhabra
  64. 64. + B6-P GCS Glycine Role in Amino Acid Metabolism  Glycine Metabolism Glycine Cleavage System CLINICAL SIGNIFICANCE dUMP dTMP Di Hydro Folate DNA Synthesis N5,10 Methylene Tetra Hydro Folate Thymidylate Synthase Carbon Dioxide Ammonia 64Biochemistry for medics- Namrata Chhabra
  65. 65. + B6-P GCS Glycine Role in Amino Acid Metabolism  Glycine Metabolism Glycine Cleavage System CLINICAL SIGNIFICANCE dUMP dTMP Di Hydro Folate DNA Synthesis Thymidylate Synthase Carbon Dioxide Ammonia N5,10 Methylene Tetra Hydro Folate 65Biochemistry for medics- Namrata Chhabra
  66. 66. GlycineAcetyl CoA + Role in Amino Acid Metabolism  Glycine Metabolism Synthesis of Amino Acetone 66Biochemistry for medics- Namrata Chhabra
  67. 67. GlycineAcetyl CoA Amino Acetone Synthetase B6-P + Role in Amino Acid Metabolism  Glycine Metabolism Synthesis of Amino Acetone 67Biochemistry for medics- Namrata Chhabra
  68. 68. Amino Acetone GlycineAcetyl CoA Amino Acetone Synthetase B6-P + Role in Amino Acid Metabolism  Glycine Metabolism Synthesis of Amino Acetone CLINICAL SIGNIFICANCE  Amino Acetone has a role in Metabolism† † Elliott, W.H., et al., 1959. Amino Acteone: Its Isolation and Role in Metabolism, Canberra. Nature: 183, 1051-1052. 68Biochemistry for medics- Namrata Chhabra
  69. 69.  Sources of Vitamin B6  Structure of Vitamin B6  Activation of Vitamin B6  Role in Amino Acid Metabolism  General Amino Acid Reactions  Metabolism of Tryptophan  Metabolism of Methionine  Metabolism of Glycine SUMMARY 69Biochemistry for medics- Namrata Chhabra
  70. 70.  Biehl, J.P., et al., 1954. Effect of Isoniazid on Vitamin B6 Metabolism; Its Possible Significance in Producing Isoniazid Neuritis, London. Royal Society of Medicine Press; 85:389-392.  Robinson, K., et al., 1996. Hyperhomocysteinemia Confers an Independent Increased Risk of Atherosclerosis in End-Stage Renal Disease and Is Closely Linked to Plasma Folate and Pyridoxine Concentrations, Boston. Circulation; 94:2743-2748 Bibliography  Chatterjea, M.N., Shinde, R., 2008. Textbook of Medical Biochemistry, 7th Edition, New Delhi. Jaypee.  Murray, R.K., et al., 2009. Harper’s Illustrated Biochemistry, 28th Edition, New York. McGraw Hill.  Champe, C., et al., 2008. Lippincott’s Illustrated Review of Biochemistry, 4th Edition , New York. Lippincott Williams and Wilkins.  Chabba, N., 2011. Vitamin B6 chemistry, Activation and Role in Amino Acid Metabolism. Biochemistry Lecture, Mauritius, SSR Medical College. UNPUBLISHED. 70Biochemistry for medics- Namrata Chhabra
  71. 71. 71Biochemistry for medics- Namrata Chhabra

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