Metabolism of Vitamins and Trace Elements

General PrefacePreface to Section IVChapter I. Metabolism of Water-Soluble VitaminsSection a. The Biosynthesis of Thiamine 1. Introduction 2. Enzymatic Synthesis of Thiamine 3. Enzymatic Synthesis of Thiamine-PP 4. Biogenesis of the Pyrimidine MOiety 5. Biogenesis of Thiazole ReferencesChapter I. Metabolism of Water-Soluble VitaminsSection b. The Biosynthesis of Riboflavin 1. Introduction 2. Formation of Riboflavin from 6,7-Dimethyl-8-Ribityllumazine a. Isolation and Chemical Synthesis of 6,7-Dimethyl-8-Ribityllumazine and Derivatives b. 6,7-Dimethyl-8-Ribityllumazine as Precursor of Riboflavin c. Stoichiometry of the Riboflavin Synthetase Reaction d. Substrate Specificity of the Riboflavin Synthetase Reaction e. Purification and Certain Properties of Riboflavin Synthetase 3. Mechanism of Riboflavin Synthetase from Yeast a. Complexes of the Enzyme with Lumazine Derivatives and Riboflavin b. Kinetics c. Binding of 4-Carbon Donor and Acceptor d. Evidence for Existence of a Ternary Complex e. Studies of Nature of Reaction Intermediates 4. Biosynthesis of 6,7-Dimethyl-8-Ribityllumazine ReferencesChapter I. Metabolism of Water-Soluble VitaminsSection c. The Metabolism of Vitamin B6 1. Introduction 2. Biosynthesis of Vitamin B6 3. Absorption and Transport of Vitamin B6 4. Interconversion of Various Forms of Vitamin B6 a. Phosphorylation of Pyridoxine, Pyridoxal and Pyridoxamine b. Interconversion of Pyridoxine 5'-Phosphate, Pyridoxamine 5'-Phosphate, and Pyridoxal 5'-Phosphate c. Hydrolysis of Vitamin B6 5'-Phosphates to Free Vitamin B6 d. Interconversion of Free Pyridoxine, Pyridoxal and Pyridoxamine 5. Preferred Pathways for Pyridoxal-P Formation and Control of Vitamin B6 Metabolism 6. Catabolism of Vitamin B6 a. In Animals b. In Microorganisms 7. Abnormalities in Vitamin B6 Metabolism ReferencesChapter I. Metabolism of Water-Soluble VitaminsSection d. Biosynthesis of Pantothenic Acid and Coenzyme A 1. Introduction 2. Biogenesis of Pantoic Acid 3. Biogenesis of ?-Alanine 4. Enzymatic Synthesis of Pantothenic Acid 5. Enzymatic Synthesis of Coenzyme A from Pantothenic Acid ReferencesChapter I. Metabolism of Water-Soluble VitaminsSection e. The Metabolism of Biotin and Analogues 1. Introduction 2. Biosynthesis a. Pimelic Acid b. Pelargonie Acid Derivatives c. Dethiobiotin d. Sulfur Sources e. Miscellaneous Factors 3. Interconversions a. Free and Bound Forms b. Thioether and Sulfoxide Forms 4. Degradations a. Side-Chain b. Bicyclic Ring System ReferencesChapter I. Metabolism of Water-Soluble VitaminsSection f. The Biosynthesis of Folic Acid and 6-Substituted Pteridine Derivatives 1. Introduction 2. The Biosynthesis of Folate Compounds a. Involvement of Purines b. GTP as the Pteridine Precursor c. Pyrimidine Derivatives as Intermediates d. Dihydroneopterin Triphosphate Synthesis e. Dihydroneopterin Triphosphate Utilization f. Hydroxymethyldihydxopterin Utilization g. Hydroxymethyldihydropterin-PP as an Intermediate h. Role of p-Aminobenzoate and p-Aminobenzoylglutamate i. Dihydrofolate synthesis 3. Pteroylpolyglutamates a. Occurrence b. Biosynthesis c. Conjugase(s) d. Assays 4. Biosynthesis of Unconjugated Pteridines a. Occurrence of Pteridines with a Side-Chain in Position 6 b. Origin of the Side-Chain of Biopterin and Sepiapterin c. The Reactions Concerning the Side-Chain of Neopterin, Biopterin and Sepiapterin d. Pterin and Hydroxypterins 5. Coenzyme Function a. Hydroxylation b. Possible Involvement in the Photosynthetic Process Acknowledgement Addendum ReferencesChapter I. Metabolism of Water-Soluble VitaminsSection g. The Metabolism of the Cobalamins 1. Introduction 2. Sources and Requirements 3. Uses of Radioactive Cobalamins in Metabolic Studies 4. Absorption of Cobalamins 5. Malabsorption of Cobalamins 6. Absorption of Vitamin B12 by Simple Diffusion 7. Vitamin B12 Binders Other than Intrinsic Factor 8. Vitamin B12 Transport in Plasma 9. Uptake of Vitamin B12 by Tissues 10. The Distribution of Vitamin B12 in Tissues 11. The Distribution of Vitamin B12 in Serum 12. The Turnover of Exogenous Cobalamins a. Tracer Studies in Rats b. Tracer Studies in Mice c. Tracer Studies in Dogs 13. Turnover Studies in Man 14. The Excretion of Cyanocobalamin 15. Interconversion of Cobalamins ReferencesChapter II. Trace Elements: Metabolism and Metabolic Function 1. Introduction 2. Iron a. Metabolism b. Chemistry c. Biochemical Function 3. Copper a. Metabolism b. Chemistry c. Biochemical Function 4. Zinc a. Metabolism b. Chemistry c. Biochemical Function 5. Cobalt a. Metabolism b. Chemistry c. Biochemical Function 6. Manganese a. Metabolism b. Chemistry c. Biochemical Function 7. Chromium a. Metabolism b. Chemistry c. Biochemical Function 8. Molybdenum a. Metabolism b. Chemistry c. Biochemical Function 9. Selenium a. Metabolism b. Chemistry c. Biochemical Function 10. Iodine a. Metabolism b. Chemistry c. Biochemical Function 11. Fluorine a. Metabolism b. Chemistry c. Biochemical Function Acknowledgements ReferencesSubject Index