Vitamin B12

Proceedings of the 3rd European Symposium on Vitamin B12 and Intrinsic Factor, University of Zurich, March 5–8, 1979, Zurich, Switzerland

B. Zagalak, W. Friedrich, 1979, Zürich> European Symposium on Vitamin B 12 and Intrinsic Factor, B. Zagalak, W. Friedrich, 1979, Zürich> European Symposium on Vitamin B 12 and Intrinsic Factor <3, Universität

• Publisher: De Gruyter
• Year: 2019
• Print ISBN: 9783110076684
• eBook ISBN: 9783111510828
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Chemistry
• Index: Biological Sciences

Table of contents

• Preface
• CONTENTS
• Chapter 1. CHEMISTRY OF CORRINOIDS. TOTAL SYNTHESIS OF VITAMIN B₁₂
• Introductory remarks for opening of 3rd European Symposium on vitamin B₁₂
• Introductory remarks. Historical perspectives on the isolation of crystalline vitamin B₁₂
• New and old problems in the structure analysis of vitamin B₁₂
• Synthetic vitamin B₁₂
• Chemical synthesis of corrinoids: current problems and recent advances
• Recent studies on the synthesis of vitamin B₁₂
• New reactions of the chromophoric system of vitamin B₁₂ derivatives
• Structure and reactivity of the so-called stable yellow corrinoids
• Concerning the structure of so-called yellow products obtained from naturally occurring metal-free corrinoids
• Correlation of vitamin B₁₂ methanolysis products with cobyrinic methyl ester amides prepared from hydrogenobyrinic acid amides
• Preparation and X-ray structural analyses of a cobyrinic acid diamide and the corresponding rhodium analogue
• Concerning a new corrinoid from municipal sludge
• Steric course of the substitution by vitamin B_12s as studied by ¹H-NMR spectroscopy
• Synthesis and X-ray analysis of a porphyrin-type Co(I)-complex
• Stereochemistry of the formation and cleavage of the Co-C bond in a vitamin B₁₂ model
• The structure of superoxocobalamin, a single crystal ESR study
• NMR studies of a novel form of vitamin B₁₂
• Circular dichroism study of organocobalamins
• Concerning electronic, CD and ORD spectra of isomeric pairs of several (Co-methyl)-corrinoids
• Some properties of cobalaminhexacyanoferrate
• Temperature-jump kinetics of the "base-on" - "base-off" equilibrium of methylcobalamin
• Electrochemistry of vitamin B₁₂. Equilibria, kinetics and mechanisms in the B_12a - B_12r - B_12s oxido-reduction
• Electrochemistry of vitamin B₁₂. Alkyl cobalamins and cobinamides
• Chapter 2. BIOSYNTHESIS OF CORRINOIDS
• Recent biosynthetic researches on vitamin B₁₂
• Intermediary metabolism of cobyrinic acid biosynthesis
• On the methylation process in cobyrinic acid biosynthesis
• Biogenesis of tetrapyrrole compounds (porphyrins and corrinoids), and its regulation
• Factor I ex Clostridium tetanomorphum: proof of structure and relationship to vitamin B₁₂ biosynthesis
• On the biosynthesis of the 5,6-dimethylbenzimidazole moiety of vitamin B₁₂
• The enzyme system of propionic acid bacteria transforming riboflavin into 5,6-dimethylbenzimidazole
• Straight approaches to the nucleotide loop
• Ribosomal proteins share in vitamin B₁₂ biosynthesis
• The ribosomal proteins L2, L5, L18 and L25 involved in vitamin B₁₂ biosynthesis
• Formation and role of vitamin B₁₂ in Protaminobacter ruber and Rhizobium meliloti
• Chapter 3. CORRINOID DEPENDENT ENZYMES AND REACTIONS. MODEL SYSTEMS
• Current status of the mechanism of action of B₁₂ - coenzyme
• A stereochemical approach to the diol dehydratase reaction
• Coenzyme B₁₂-dependent diol dehydratase - distribution and metabolic role in Enterobacteriaceae, enzymological properties and interaction with coenzyme B₁₂
• Adenosylcobalamin-dependent glycerol dehydratase interaction with substrates and their analogs
• Glycerol dehydratase from Aerobacter aerogenes
• The mechanism of action of methylmalonyl-CoA mutase as studied with isotope labelling and synthetic models
• Recent studies on the mechanism of action of ethanolamine ammonia-lyase
• Studies on the mechanism of reactions catalysed by ethanolamine ammonia-lyase
• Steric course of the ethanolamine-ammonia lyase reaction
• The chemical synthesis and coenzymatic properties of analogs of adenosylcobalamin in the ribonucleotide reductase reaction
• Review of the EPR of B_12r and B₁₂ -dependent enzyme reactions
• Vitamin B₁₂: current problems and recent advances
• The role of corrinoids in the total synthesis of acetate from C0₂
• Mechanisms for B₁₂ -dependent methylation
• Nonenzymic models for the enigmatic coenzyme B₁₂-dependent carbon-skeleton rearrangements
• The mechanism of action of coenzyme B₁₂
• Model systems for adenosylcobalamin dependent enzymic reactions
• Bridged cobaloximes as vitamin B₁₂ models
• Modified adenosylaobalamin: model systems for the active sites of corrinoid-dependent enzymes
• Chapter 4. ANALOGUES AND ANTAGONISTS OF VITAMIN B₁₂
• Naturally occurring vitamin B₁₂ antagonists and their potential therapeutic value
• Structures of some vitamin B₁₂ analogues and their biological as well as biochemical functions
• Novel metal-free corrinoids and metal analogues
• Preparation of ferribalamin, the Fe(III)-analogue of vitamin B₁₂
• Chapter 5. VITAMIN B₁₂ ASSAY
• Vitamin B₁₂ assay: an evaluation of radiodilution assay using cobinamide to increase specificity
• Effect of residual extract products and the type of binders (R or IF) on serum vitamin B₁₂ levels by radioisotope dilution assay
• Differential assay of cobamides in serum using R-protein radioisotopic dilution assay, E.coli and E.gracilis assays
• Rapid determination of corrinoids by high performance liquid chromatography
• Determination of the plasma cobalamins by one-dimensional thin-layer chromatography
• Chemical quantitation of corrinoids
• Enzymatic estimation of vitamin B₁₂
• Essential prerequisites for the analysis of cyanocobalamin in biochemically complex samples using radiometric competitive binding assays
• Chapter 6. ABSORPTION, TRANSPORT AND DISTRIBUTION OF VITAMIN B₁₂
• Distribution of cobalamins in the animal body
• Vitamin B₁₂ in membrane mimetic agents - theoretical considerations and practical applications
• Transport of vitamin B₁₂ in Escherichia coli
• The plasma transport of cobalamin (Cbl)
• Soluble and membrane-bound vitamin B₁₂ transport proteins
• The origin and clinical implications of vitamin B₁₂ binders - the transcobalamins
• Large vitamin B₁₂-binding proteins and complexes in human serum
• Heterogeneity of antibodies against B₁₂ binders in pernicious anaemia
• The intraluminal phase of vitamin B₁₂ transport in humans
• Polymorphic variants of transcobalamin II rare alleles in family studies
• Relationship between cobalophilin releasing and functional state of polymorphonuclear granulocytes
• The significance of vitamin B₁₂ binders in the central nervous system
• In vitro acid dissociation of cobalamin-transcobalamin II complexes formed in vivo: a probe in the study of TC II-kinetics
• Calcium dependencies in the binding of transcobalamins to subcellular particles of liver cells
• The effect of antibiotics on transcobalamin II synthesis in rabbit liver cell culture
• Solubilization and characterization of the transcobalamin II acceptor from human placenta and rabbit liver
• Strength of binding of methyl-, 5 '-deoxyadenosyl-, cyano- and hydroxocobalamin to human transcobalamin I and II and intrinsic factor
• Adsorptive endocytosis of transcobalamin II-vitamin B₁₂ by isolated rat liver parenchymal cells
• Species specificity between TC II, TC II-Cbl uptake and anti-TC II
• Transcobalamin II polymorphism in african populations
• Transcobalamins during induction of nutritional cobalamin deficiency in the fruit bat
• Heterogeneity of transcobalamin II demonstrated by isoelectric focusing in urea
• Radioimmunosorbent determinations of unsaturated and total transcobalamin II in human serum
• The "dU suppression test" and "thymidine suppression test": evidence for reciprocal relationship between the "de novo" and "salvage" pathways of DNA synthesis
• TC II deficiency: observations with deoxyuridine suppression test
• Spectral studies on hog intrinsic factor and hog non-intrinsic factor
• Amino terminal sequence of hog non-intrinsic factor and hog intrinsic factor
• Subunit structure of the pig ileal intrinsic factor receptor
• Cobinamide blocking assay for intrinsic factor
• Intracelular transport of vitamin B₁₂ in enterocytes
• Evidence for the chief cell as the source of intrinsic factor secretion in the rat
• Long-term treatment of pernicious anemia patients with intrinsic factor
• An analogy of cobalamin membrane transport: an intestinal receptor for heme
• A simplified method for quantitative determination of vitamin B₁₂ absorption
• Vitamin B₁₂ absorption studies with plastic whole body counter in patients with gastroenterological operation
• Affinity photo-release purification of cobalamin-binding proteins
• Effect of pentagastrin in vitamin B₁₂ absorption in the guinea pig
• Synthesis of cobalamin coenzymes in the rat and their secretion from the liver into plasma and bile
• The pattern of cobalamins in human erythrocytes
• Presence of sulfitocobalamin in cell extracts. Resolution and identification by SP-Sephadex C-25 cation exchange chromatography
• Mitochondrial cobalamins: types, sources, and functions with evidence of their noninvolvement in mitochondrial DNA synthesis
• Chapter 7. PHYSIOLOGY AND PATHOLOGY OF VITAMIN B₁₂
• Studies on vitamin B₁₂ and ubiquinone
• Haematological aspects of cobalamin deficiency
• The neurology of vitamin B₁₂ deficiency
• Clinioal diseases related to defioienoies of vitamin B₁₂ transport proteins
• Effects of methylaobalamin on peripheral neuropathies or experimentally-induced neuropathies
• Inherited deficiencies of the deoxyadenosylcobalamin (Ado-Cbl) dependent L-methylmalonyl-CoA mutase system: clinical and biochemical aspects
• An investigation of a possible role for coenzyme B₁₂ in ribonucleotide reduction in rabbit bone marrow
• Participation of cAMP in regulation of coenzyme B₁₂ dependent glycerol dehydratase synthesis from Klebsiella pneumoniae ATCC 85955
• Carbon monoxide oxidation by Clostridia: evidence for the involvement of a corrinoid-like compound
• The in vivo effects of nitrous oxide on human bone marrow - a morphological, biochemical and cell cycle study
• Interconversion of cobalamins in human lymphocytes in vitro and the influence of nitrous oxide on synthesis of cobalamin coenzymes
• Studies on cobalamin and folate metabolism in rats exposed to nitrous oxide (N₂O)
• Alterations in mammalian cells induced by inactivation of vitamin B₁₂ with nitrous oxide
• High ascorbic acid intake and vitamin B₁₂ status in the rat
• 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)
• Interaction between methylcobalamin and some amino acids in single cell proteins
• Methylcobalamin and the modification of proteins in vitro
• Deoxyadenosylcobalamin and the process of methylation of tRNA in model systems
• The participation of coenzyme B₁₂ in the synthesis of DNA by Propionibacterium shermanii
• Recent advances in cobalamin metabolism: abnormalities in coenzyme distribution in tumor development and in inherited metabolic disease
• On some properties of the effect and metabolism of different cobalamins in tumor-bearing rats
• Gastric cancer as a risk factor in pernicious anaemia
• Interference with cobalamin metabolism and tumour growth by an analogue of methylcobalamin
• Vitamin B₁₂ requirement for replication of mouse leukemia L1210 cells: functional relevance to folate metabolism
• Vitamin B₁₂ and folia acid interrelations: a new look
• The effect of hypothyroidism on histidine oxidation and folate-dependent enzyme levels
• Cobalamin-dependent methionine synthesis and the regulation of the metabolism of activated folic acid derivatives in cultured human lymphoblasts
• Author and Citation Index
• Subject Index
• Collection of Photographs from the Symposium