ویتامین B۱۲: مجموعه مقالات سومین سمپوزیوم اروپایی درباره ویتامین B۱۲ و فاکتور داخلی، دانشگاه زوریخ، ۵ تا ۸ مارس ۱۹۷۹، زوریخ، سوئیس ۲۰۱۹
Vitamin B12: Proceedings of the 3rd European Symposium on Vitamin B12 and Intrinsic Factor, University of Zurich, March 5–8, 1979, Zurich, Switzerland 2019

1. Preface

2. CONTENTS

3. Chapter 1. CHEMISTRY OF CORRINOIDS. TOTAL SYNTHESIS OF VITAMIN B₁₂

4. Introductory remarks for opening of 3rd European Symposium on vitamin B₁₂

5. Introductory remarks. Historical perspectives on the isolation of crystalline vitamin B₁₂

6. New and old problems in the structure analysis of vitamin B₁₂

7. Synthetic vitamin B₁₂

8. Chemical synthesis of corrinoids: current problems and recent advances

9. Recent studies on the synthesis of vitamin B₁₂

10. New reactions of the chromophoric system of vitamin B₁₂ derivatives

11. Structure and reactivity of the so-called stable yellow corrinoids

12. Concerning the structure of so-called yellow products obtained from naturally occurring metal-free corrinoids

13. Correlation of vitamin B₁₂ methanolysis products with cobyrinic methyl ester amides prepared from hydrogenobyrinic acid amides

14. Preparation and X-ray structural analyses of a cobyrinic acid diamide and the corresponding rhodium analogue

15. Concerning a new corrinoid from municipal sludge

16. Steric course of the substitution by vitamin B_12s as studied by ¹H-NMR spectroscopy

17. Synthesis and X-ray analysis of a porphyrin-type Co(I)-complex

18. Stereochemistry of the formation and cleavage of the Co-C bond in a vitamin B₁₂ model

19. The structure of superoxocobalamin, a single crystal ESR study

20. NMR studies of a novel form of vitamin B₁₂

21. Circular dichroism study of organocobalamins

22. Concerning electronic, CD and ORD spectra of isomeric pairs of several (Co-methyl)-corrinoids

23. Some properties of cobalaminhexacyanoferrate

24. Temperature-jump kinetics of the "base-on" - "base-off" equilibrium of methylcobalamin

25. Electrochemistry of vitamin B₁₂. Equilibria, kinetics and mechanisms in the B_12a - B_12r - B_12s oxido-reduction

26. Electrochemistry of vitamin B₁₂. Alkyl cobalamins and cobinamides

27. Chapter 2. BIOSYNTHESIS OF CORRINOIDS

28. Recent biosynthetic researches on vitamin B₁₂

29. Intermediary metabolism of cobyrinic acid biosynthesis

30. On the methylation process in cobyrinic acid biosynthesis

31. Biogenesis of tetrapyrrole compounds (porphyrins and corrinoids), and its regulation

32. Factor I ex Clostridium tetanomorphum: proof of structure and relationship to vitamin B₁₂ biosynthesis

33. On the biosynthesis of the 5,6-dimethylbenzimidazole moiety of vitamin B₁₂

34. The enzyme system of propionic acid bacteria transforming riboflavin into 5,6-dimethylbenzimidazole

35. Straight approaches to the nucleotide loop

36. Ribosomal proteins share in vitamin B₁₂ biosynthesis

37. The ribosomal proteins L2, L5, L18 and L25 involved in vitamin B₁₂ biosynthesis

38. Formation and role of vitamin B₁₂ in Protaminobacter ruber and Rhizobium meliloti

39. Chapter 3. CORRINOID DEPENDENT ENZYMES AND REACTIONS. MODEL SYSTEMS

40. Current status of the mechanism of action of B₁₂ - coenzyme

41. A stereochemical approach to the diol dehydratase reaction

42. Coenzyme B₁₂-dependent diol dehydratase - distribution and metabolic role in Enterobacteriaceae, enzymological properties and interaction with coenzyme B₁₂

43. Adenosylcobalamin-dependent glycerol dehydratase interaction with substrates and their analogs

44. Glycerol dehydratase from Aerobacter aerogenes

45. The mechanism of action of methylmalonyl-CoA mutase as studied with isotope labelling and synthetic models

46. Recent studies on the mechanism of action of ethanolamine ammonia-lyase

47. Studies on the mechanism of reactions catalysed by ethanolamine ammonia-lyase

48. Steric course of the ethanolamine-ammonia lyase reaction

49. The chemical synthesis and coenzymatic properties of analogs of adenosylcobalamin in the ribonucleotide reductase reaction

50. Review of the EPR of B_12r and B₁₂ -dependent enzyme reactions

51. Vitamin B₁₂: current problems and recent advances

52. The role of corrinoids in the total synthesis of acetate from C0₂

53. Mechanisms for B₁₂ -dependent methylation

54. Nonenzymic models for the enigmatic coenzyme B₁₂-dependent carbon-skeleton rearrangements

55. The mechanism of action of coenzyme B₁₂

56. Model systems for adenosylcobalamin dependent enzymic reactions

57. Bridged cobaloximes as vitamin B₁₂ models

58. Modified adenosylaobalamin: model systems for the active sites of corrinoid-dependent enzymes

59. Chapter 4. ANALOGUES AND ANTAGONISTS OF VITAMIN B₁₂

60. Naturally occurring vitamin B₁₂ antagonists and their potential therapeutic value

61. Structures of some vitamin B₁₂ analogues and their biological as well as biochemical functions

62. Novel metal-free corrinoids and metal analogues

63. Preparation of ferribalamin, the Fe(III)-analogue of vitamin B₁₂

64. Chapter 5. VITAMIN B₁₂ ASSAY

65. Vitamin B₁₂ assay: an evaluation of radiodilution assay using cobinamide to increase specificity

66. Effect of residual extract products and the type of binders (R or IF) on serum vitamin B₁₂ levels by radioisotope dilution assay

67. Differential assay of cobamides in serum using R-protein radioisotopic dilution assay, E.coli and E.gracilis assays

68. Rapid determination of corrinoids by high performance liquid chromatography

69. Determination of the plasma cobalamins by one-dimensional thin-layer chromatography

70. Chemical quantitation of corrinoids

71. Enzymatic estimation of vitamin B₁₂

72. Essential prerequisites for the analysis of cyanocobalamin in biochemically complex samples using radiometric competitive binding assays

73. Chapter 6. ABSORPTION, TRANSPORT AND DISTRIBUTION OF VITAMIN B₁₂

74. Distribution of cobalamins in the animal body

75. Vitamin B₁₂ in membrane mimetic agents - theoretical considerations and practical applications

76. Transport of vitamin B₁₂ in Escherichia coli

77. The plasma transport of cobalamin (Cbl)

78. Soluble and membrane-bound vitamin B₁₂ transport proteins

79. The origin and clinical implications of vitamin B₁₂ binders - the transcobalamins

80. Large vitamin B₁₂-binding proteins and complexes in human serum

81. Heterogeneity of antibodies against B₁₂ binders in pernicious anaemia

82. The intraluminal phase of vitamin B₁₂ transport in humans

83. Polymorphic variants of transcobalamin II rare alleles in family studies

84. Relationship between cobalophilin releasing and functional state of polymorphonuclear granulocytes

85. The significance of vitamin B₁₂ binders in the central nervous system

86. In vitro acid dissociation of cobalamin-transcobalamin II complexes formed in vivo: a probe in the study of TC II-kinetics

87. Calcium dependencies in the binding of transcobalamins to subcellular particles of liver cells

88. The effect of antibiotics on transcobalamin II synthesis in rabbit liver cell culture

89. Solubilization and characterization of the transcobalamin II acceptor from human placenta and rabbit liver

90. Strength of binding of methyl-, 5 '-deoxyadenosyl-, cyano- and hydroxocobalamin to human transcobalamin I and II and intrinsic factor

91. Adsorptive endocytosis of transcobalamin II-vitamin B₁₂ by isolated rat liver parenchymal cells

92. Species specificity between TC II, TC II-Cbl uptake and anti-TC II

93. Transcobalamin II polymorphism in african populations

94. Transcobalamins during induction of nutritional cobalamin deficiency in the fruit bat

95. Heterogeneity of transcobalamin II demonstrated by isoelectric focusing in urea

96. Radioimmunosorbent determinations of unsaturated and total transcobalamin II in human serum

97. The "dU suppression test" and "thymidine suppression test": evidence for reciprocal relationship between the "de novo" and "salvage" pathways of DNA synthesis

98. TC II deficiency: observations with deoxyuridine suppression test

99. Spectral studies on hog intrinsic factor and hog non-intrinsic factor

100. Amino terminal sequence of hog non-intrinsic factor and hog intrinsic factor

101. Subunit structure of the pig ileal intrinsic factor receptor

102. Cobinamide blocking assay for intrinsic factor

103. Intracelular transport of vitamin B₁₂ in enterocytes

104. Evidence for the chief cell as the source of intrinsic factor secretion in the rat

105. Long-term treatment of pernicious anemia patients with intrinsic factor

106. An analogy of cobalamin membrane transport: an intestinal receptor for heme

107. A simplified method for quantitative determination of vitamin B₁₂ absorption

108. Vitamin B₁₂ absorption studies with plastic whole body counter in patients with gastroenterological operation

109. Affinity photo-release purification of cobalamin-binding proteins

110. Effect of pentagastrin in vitamin B₁₂ absorption in the guinea pig

111. Synthesis of cobalamin coenzymes in the rat and their secretion from the liver into plasma and bile

112. The pattern of cobalamins in human erythrocytes

113. Presence of sulfitocobalamin in cell extracts. Resolution and identification by SP-Sephadex C-25 cation exchange chromatography

114. Mitochondrial cobalamins: types, sources, and functions with evidence of their noninvolvement in mitochondrial DNA synthesis

115. Chapter 7. PHYSIOLOGY AND PATHOLOGY OF VITAMIN B₁₂

116. Studies on vitamin B₁₂ and ubiquinone

117. Haematological aspects of cobalamin deficiency

118. The neurology of vitamin B₁₂ deficiency

119. Clinioal diseases related to defioienoies of vitamin B₁₂ transport proteins

120. Effects of methylaobalamin on peripheral neuropathies or experimentally-induced neuropathies

121. Inherited deficiencies of the deoxyadenosylcobalamin (Ado-Cbl) dependent L-methylmalonyl-CoA mutase system: clinical and biochemical aspects

122. An investigation of a possible role for coenzyme B₁₂ in ribonucleotide reduction in rabbit bone marrow

123. Participation of cAMP in regulation of coenzyme B₁₂ dependent glycerol dehydratase synthesis from Klebsiella pneumoniae ATCC 85955

124. Carbon monoxide oxidation by Clostridia: evidence for the involvement of a corrinoid-like compound

125. The in vivo effects of nitrous oxide on human bone marrow - a morphological, biochemical and cell cycle study

126. Interconversion of cobalamins in human lymphocytes in vitro and the influence of nitrous oxide on synthesis of cobalamin coenzymes

127. Studies on cobalamin and folate metabolism in rats exposed to nitrous oxide (N₂O)

128. Alterations in mammalian cells induced by inactivation of vitamin B₁₂ with nitrous oxide

129. High ascorbic acid intake and vitamin B₁₂ status in the rat

130. Ability of megadoses of vitamin C to destroy vitamin B₁₂ and cobinamide and to reduce absorption of vitamin B₁₂ (with a note on B₁₂ radioassays)

131. Interaction between methylcobalamin and some amino acids in single cell proteins

132. Methylcobalamin and the modification of proteins in vitro

133. Deoxyadenosylcobalamin and the process of methylation of tRNA in model systems

134. The participation of coenzyme B₁₂ in the synthesis of DNA by Propionibacterium shermanii

135. Recent advances in cobalamin metabolism: abnormalities in coenzyme distribution in tumor development and in inherited metabolic disease

136. On some properties of the effect and metabolism of different cobalamins in tumor-bearing rats

137. Gastric cancer as a risk factor in pernicious anaemia

138. Interference with cobalamin metabolism and tumour growth by an analogue of methylcobalamin

139. Vitamin B₁₂ requirement for replication of mouse leukemia L1210 cells: functional relevance to folate metabolism

140. Vitamin B₁₂ and folia acid interrelations: a new look

141. The effect of hypothyroidism on histidine oxidation and folate-dependent enzyme levels

142. Cobalamin-dependent methionine synthesis and the regulation of the metabolism of activated folic acid derivatives in cultured human lymphoblasts

143. Author and Citation Index

144. Subject Index

145. Collection of Photographs from the Symposium