101
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Zhang Y, Gladyshev VN. Comparative genomics of trace element dependence in biology. J Biol Chem 2011; 286:23623-9. [PMID: 21566146 DOI: 10.1074/jbc.r110.172833] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Biological trace elements are needed in small quantities but are used by all living organisms. A growing list of trace element-dependent proteins and trace element utilization pathways highlights the importance of these elements for life. In this minireview, we focus on recent advances in comparative genomics of trace elements and explore the evolutionary dynamics of the dependence of user proteins on these elements. Many zinc protein families evolved representatives that lack this metal, whereas selenocysteine in proteins is dynamically exchanged with cysteine. Several other elements, such as molybdenum and nickel, have a limited number of user protein families, but they are strictly dependent on these metals. Comparative genomics of trace elements provides a foundation for investigating the fundamental properties, functions, and evolutionary dynamics of trace element dependence in biology.
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Affiliation(s)
- Yan Zhang
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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102
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Plesa M, Kim J, Paquette SG, Gagnon H, Ng-Thow-Hing C, Gibbs BF, Hancock MA, Rosenblatt DS, Coulton JW. Interaction between MMACHC and MMADHC, two human proteins participating in intracellular vitamin B₁₂ metabolism. Mol Genet Metab 2011; 102:139-48. [PMID: 21071249 DOI: 10.1016/j.ymgme.2010.10.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Revised: 10/15/2010] [Accepted: 10/15/2010] [Indexed: 11/22/2022]
Abstract
The identification of eight genes involved in inherited cobalamin (Cbl) disorders has provided insight into the complexity of the vitamin B₁₂ trafficking pathway. Detailed knowledge about the structure, interaction, and physiological functions for many of the gene products, including the MMACHC and MMADHC proteins, is lacking. Having cloned, expressed, and purified MMACHC in Escherichia coli, we demonstrated its monodispersity by dynamic light scattering and measured its hydrodynamic radius, either alone or in complex with each of four vitamin B₁₂ derivatives. Using solution-phase intrinsic fluorescence and label-free, real-time surface plasmon resonance (SPR), MMACHC bound cyanocobalamin and hydroxycobalamin with similar low micromolar affinities (K(D) 6.4 and 9.8 μM, respectively); adenosylcobalamin and methylcobalamin also shared similar binding affinities for MMACHC (K(D) 1.7 and 1.4 μM, respectively). To predict specific regions of interaction between MMACHC and the proposed partner protein MMADHC, MMACHC was subjected to phage display. Five putative MMACHC-binding sites were identified. Finally, MMADHC was confirmed as a binding partner for MMACHC both in vitro (SPR) and in vivo (bacterial two-hybrid system).
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Affiliation(s)
- Maria Plesa
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
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103
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Hathout L, El-Saden S. Nitrous oxide-induced B12 deficiency myelopathy: Perspectives on the clinical biochemistry of vitamin B12. J Neurol Sci 2011; 301:1-8. [DOI: 10.1016/j.jns.2010.10.033] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 10/28/2010] [Accepted: 10/29/2010] [Indexed: 11/28/2022]
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104
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Aravindu K, Krayer M, Kim HJ, Lindsey JS. Facile synthesis of a B,D-tetradehydrocorrin and rearrangement to bacteriochlorins. NEW J CHEM 2011. [DOI: 10.1039/c1nj20027e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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105
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Walter JH. Vitamin B12 deficiency and phenylketonuria. Mol Genet Metab 2011; 104 Suppl:S52-4. [PMID: 21824796 DOI: 10.1016/j.ymgme.2011.07.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Revised: 07/17/2011] [Accepted: 07/18/2011] [Indexed: 10/18/2022]
Abstract
The literature regarding the vitamin B(12) status of patients with phenylketonuria was reviewed. Adequate amounts of B(12) are provided in products used in dietary treatment; however, a number of case reports and cohort studies document deficiency in those who have discontinued taking amino acid, mineral and vitamin supplements but who continue to eat only very limited amounts of natural protein. Symptoms and signs of B(12) deficiency are variable but severe deficiency may cause serious neurological disease. Nitrous oxide anaesthesia is a particular risk. It is recommended that plasma total homocysteine and plasma or urinary methylmalonate should be routinely measured, as they are more sensitive markers of deficiency than serum B(12) concentrations. Functional B(12) deficiency can occur in the presence of a normal B(12) concentration.
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Affiliation(s)
- John H Walter
- Medicine, Manchester Academic Health Sciences Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom.
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106
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Abstract
Vitamin B12 (cobalamin, Cbl) is an essential nutrient in human metabolism. Genetic diseases of vitamin B12 utilisation constitute an important fraction of inherited newborn disease. Functionally, B12 is the cofactor for methionine synthase and methylmalonyl CoA mutase. To function as a cofactor, B12 must be metabolised through a complex pathway that modifies its structure and takes it through subcellular compartments of the cell. Through the study of inherited disorders of vitamin B12 utilisation, the genes for eight complementation groups have been identified, leading to the determination of the general structure of vitamin B12 processing and providing methods for carrier testing, prenatal diagnosis and approaches to treatment.
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107
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Abstract
PURPOSE OF REVIEW To analyse the anti-inflammatory and antioxidant properties of vitamin B12 and evaluate current evidence on vitamin B12 status in the critically ill with systemic inflammation. RECENT FINDINGS Data on vitamin B12 status of intensive care unit patients are scarce. Cobalamins could potentially be useful agents for inhibiting nitric oxide synthase and nitric oxide production, controlling nuclear factor-kappa B activation, and restoring optimal bacteriostasis and phagocytosis in which transcobalamins play a proven role. The antioxidant properties of vitamin B12, with a glutathione-sparing effect, are secondary to stimulation of methionine synthase activity and reaction with free oxygen or nitrogen radicals. Large parenteral doses are routinely administered for cyanide poisoning, with only mild, reversible side-effects. Current evidence suggests that high-dose parenteral vitamin B12 may prove an innovative approach to treat critically ill systemic inflammatory response syndrome patients, especially those with severe sepsis/septic shock. In this setting, vitamin B12 and transcobalamins could modulate systemic inflammation contributing to the anti-inflammatory cascade and potentially improve outcome. SUMMARY Despite evidence from animal studies, so far there are no clinical intervention trials that have studied vitamin B12 as a pharmaconutrient strategy for critical care. Well designed animal and clinical studies are required to clarify several outstanding questions on the optimal posology, safety, and efficacy of high-dose vitamin B12 in the critically ill.
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Affiliation(s)
- William Manzanares
- Department of Critical Care Medicine, Hospital de Clínicas, Dr Manuel Quintela, Faculty of Medicine, (University Hospital), Universidad de la República, UDELAR, Montevideo, Uruguay.
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108
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Journot G, Letondor C, Neier R, Stoeckli-Evans H, Savoia D, Gualandi A. Catalytic Hydrogenation ofmeso-Octamethylporphyrinogen (Calix[4]pyrrole). Chemistry 2010; 16:4224-30. [DOI: 10.1002/chem.200903464] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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109
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Goodman AL, McNulty NP, Zhao Y, Leip D, Mitra RD, Lozupone CA, Knight R, Gordon JI. Identifying genetic determinants needed to establish a human gut symbiont in its habitat. Cell Host Microbe 2009; 6:279-89. [PMID: 19748469 DOI: 10.1016/j.chom.2009.08.003] [Citation(s) in RCA: 500] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 06/08/2009] [Accepted: 08/13/2009] [Indexed: 02/06/2023]
Abstract
The human gut microbiota is a metabolic organ whose cellular composition is determined by a dynamic process of selection and competition. To identify microbial genes required for establishment of human symbionts in the gut, we developed an approach (insertion sequencing, or INSeq) based on a mutagenic transposon that allows capture of adjacent chromosomal DNA to define its genomic location. We used massively parallel sequencing to monitor the relative abundance of tens of thousands of transposon mutants of a saccharolytic human gut bacterium, Bacteroides thetaiotaomicron, as they established themselves in wild-type and immunodeficient gnotobiotic mice, in the presence or absence of other human gut commensals. In vivo selection transforms this population, revealing functions necessary for survival in the gut: we show how this selection is influenced by community composition and competition for nutrients (vitamin B(12)). INSeq provides a broadly applicable platform to explore microbial adaptation to the gut and other ecosystems.
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Affiliation(s)
- Andrew L Goodman
- Center for Genome Sciences, Washington University School of Medicine, St. Louis, MO 63108, USA
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110
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Birch CS, Brasch NE, McCaddon A, Williams JHH. A novel role for vitamin B(12): Cobalamins are intracellular antioxidants in vitro. Free Radic Biol Med 2009; 47:184-8. [PMID: 19409980 DOI: 10.1016/j.freeradbiomed.2009.04.023] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 04/14/2009] [Accepted: 04/22/2009] [Indexed: 01/29/2023]
Abstract
Oxidative stress is a feature of many chronic inflammatory diseases. Such diseases are associated with up-regulation of a vitamin B(12) (cobalamin) blood transport protein and its membrane receptor, suggesting a link between cobalamin and the cellular response to inflammation. The ability of cobalamin to regulate inflammatory cytokines suggests that it may have antioxidative properties. Here we show that cobalamins, including the novel thiolatocobalamins N-acetyl-l-cysteinylcobalamin and glutathionylcobalamin, are remarkably effective antioxidants in vitro. We also show that thiolatocobalamins have superior efficacy compared with other cobalamin forms, other cobalamins in combination with N-acetyl-l-cysteine (NAC) or glutathione (GSH), and NAC or GSH alone. Pretreatment of Sk-Hep-1 cells with thiolatocobalamins afforded robust protection (>90% cell survival) against exposure to 30 microM concentrations of the pro-oxidants homocysteine and hydrogen peroxide. The compounds inhibited intracellular peroxide production, maintained intracellular glutathione levels, and prevented apoptotic and necrotic cell death. Moreover, thiolatocobalamins are remarkably nontoxic in vitro at supraphysiological concentrations (>2 mM). Our results demonstrate that thiolatocobalamins act as powerful but benign antioxidants at pharmacological concentrations. Because inflammatory oxidative stress is a component of many conditions, including atherosclerosis, dementia, and trauma, their utility in treating such disorders merits further investigation.
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Affiliation(s)
- Catherine S Birch
- Chester Centre for Stress Research, University of Chester, Parkgate Road, Chester CH1 4BJ, UK
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111
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Zhang Y, Gladyshev VN. Comparative Genomics of Trace Elements: Emerging Dynamic View of Trace Element Utilization and Function. Chem Rev 2009; 109:4828-61. [DOI: 10.1021/cr800557s] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Yan Zhang
- Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588-0664
| | - Vadim N. Gladyshev
- Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588-0664
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112
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Blangy V, Heiss C, Khlebnikov V, Letondor C, Stoeckli-Evans H, Neier R. Synthese, Struktur und Komplexierungseigenschaften von partiell und vollständig reduziertenmeso-Octamethylporphyrinogenen (Calix[4]pyrrolen). Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200804937] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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113
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Blangy V, Heiss C, Khlebnikov V, Letondor C, Stoeckli-Evans H, Neier R. Synthesis, Structure, and Complexation Properties of Partially and Completely Reduced meso-Octamethylporphyrinogens (Calix[4]pyrroles). Angew Chem Int Ed Engl 2008; 48:1688-91. [DOI: 10.1002/anie.200804937] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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114
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Gomes J, Castro BD, Rangel M. EPR Study of the Photolysis of Methyl- and Adenosylcobinamides in the Presence of Phosphine and Pyridine Bases. Evidence for the Need of a Judicious Choice of Irradiation Temperature and Solvent to Assess Ligand Binding. Organometallics 2008. [DOI: 10.1021/om700837d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- João Gomes
- Requimte, Departamento de Química, Faculdade de Ciências, Universidade do Porto, 4160-007 Porto, Portugal, and Requimte, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4099-003 Porto, Portugal
| | - Baltazar de Castro
- Requimte, Departamento de Química, Faculdade de Ciências, Universidade do Porto, 4160-007 Porto, Portugal, and Requimte, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4099-003 Porto, Portugal
| | - Maria Rangel
- Requimte, Departamento de Química, Faculdade de Ciências, Universidade do Porto, 4160-007 Porto, Portugal, and Requimte, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4099-003 Porto, Portugal
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115
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Fan C, Bobik TA. The PduX enzyme of Salmonella enterica is an L-threonine kinase used for coenzyme B12 synthesis. J Biol Chem 2008; 283:11322-9. [PMID: 18308727 DOI: 10.1074/jbc.m800287200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Here, the PduX enzyme of Salmonella enterica is shown to be an L-threonine kinase used for the de novo synthesis of coenzyme B(12) and the assimilation of cobyric acid (Cby). PduX with a C-terminal His tag (PduX-His(6)) was produced at high levels in Escherichia coli, purified by nickel affinity chromatography, and partially characterized. (31)P NMR spectroscopy established that purified PduX-His(6) catalyzed the conversion of l-threonine and ATP to L-threonine-O-3-phosphate and ADP. Enzyme assays showed that ATP was the preferred substrate compared with GTP, CTP, or UTP. PduX displayed Michaelis-Menten kinetics with respect to both ATP and l-threonine and nonlinear regression was used to determine the following kinetic constants: V(max) = 62.1 +/- 3.6 nmol min(-1) mg of protein(-1); K(m)(, ATP) = 54.7 +/- 5.7 microm and K(m)(,Thr) = 146.1 +/- 8.4 microm. Growth studies showed that pduX mutants were impaired for the synthesis of coenzyme B(12) de novo and from Cby, but not from cobinamide, which was the expected phenotype for an L-threonine kinase mutant. The defect in Cby assimilation was corrected by ectopic expression of pduX or by supplementation of growth medium with L-threonine-O-3-phosphate, providing further support that PduX is an L-threonine kinase. In addition, a bioassay showed that a pduX mutant was impaired for the de novo synthesis of coenzyme B(12) as expected. Collectively, the genetic and biochemical studies presented here show that PduX is an L-threonine kinase used for AdoCbl synthesis. To our knowledge, PduX is the first enzyme shown to phosphorylate free L-threonine and the first L-threonine kinase shown to function in coenzyme B(12) synthesis.
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Affiliation(s)
- Chenguang Fan
- Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
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117
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Arakawa T, Kawano Y, Kataoka S, Katayama Y, Kamiya N, Yohda M, Odaka M. Structure of Thiocyanate Hydrolase: A New Nitrile Hydratase Family Protein with a Novel Five-coordinate Cobalt(III) Center. J Mol Biol 2007; 366:1497-509. [PMID: 17222425 DOI: 10.1016/j.jmb.2006.12.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2006] [Revised: 12/01/2006] [Accepted: 12/05/2006] [Indexed: 10/23/2022]
Abstract
Thiocyanate hydrolase (SCNase) of Thiobacillus thioparus THI115 is a cobalt(III)-containing enzyme catalyzing the degradation of thiocyanate to carbonyl sulfide and ammonia. We determined the crystal structures of the apo- and native SCNases at a resolution of 2.0 A. SCNases in both forms had a conserved hetero-dodecameric structure, (alphabetagamma)(4). Four alphabetagamma hetero-trimers were structurally equivalent. One alphabetagamma hetero-trimer was composed of the core domain and the betaN domain, which was located at the center of the molecule and linked the hetero-trimers with novel quaternary interfaces. In both the apo- and native SCNases, the core domain was structurally conserved between those of iron and cobalt-types of nitrile hydratase (NHase). Native SCNase possessed the post-translationally modified cysteine ligands, gammaCys131-SO(2)H and gammaCys133-SOH like NHases. However, the low-spin cobalt(III) was found to be in the distorted square-pyramidal geometry, which had not been reported before in any protein. The size as well as the electrostatic properties of the substrate-binding pocket was totally different from NHases with respect to the charge distribution and the substrate accessibility, which rationally explains the differences in the substrate preference between SCNase and NHase.
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Affiliation(s)
- Takatoshi Arakawa
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
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118
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Vitamin B(12), a chlorophyll-related analog to pheophytin a from marine brown algae, promotes neurite outgrowth and stimulates differentiation in PC12 cells. Cytotechnology 2006; 52:181-7. [PMID: 19002876 DOI: 10.1007/s10616-006-9038-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Accepted: 11/18/2006] [Indexed: 10/23/2022] Open
Abstract
We previously isolated an analog to chlorophyll-related compounds, pheophytin a, from the marine brown alga Sargassum fulvellum and demonstrated that it is a neurodifferentiation compound. In the current study, we investigated the effects of the pheophytin a analog vitamin B(12) on PC12 cell differentiation. In the presence of a low level of nerve growth factor (10 ng ml(-1)), vitamin B(12 )demonstrated neurite outgrowth-promoting activity in PC12 cells. The effect was dose-dependent in the range of 6-100 muM. In the absence of nerve growth factor, vitamin B(12) did not promote differentiation. To investigate the mechanism for this effect, we conducted differentiation assays and western blot analysis with signal transduction inhibitors and found that vitamin B(12) did not promote PC12 cell differentiation in the presence of K252a or U0126 inhibitors. These results suggest that vitamin B(12 )stimulates PC12 cell differentiation through enhancement of the mitogen-activated protein kinase signal transduction pathway, which is also induced by nerve growth factor. Thus, vitamin B(12) may be a good candidate for treatment of neurodegenerative diseases such as Alzheimer's disease.
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119
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Suarez-Moreira E, Hannibal L, Smith CA, Chavez RA, Jacobsen DW, Brasch NE. A simple, convenient method to synthesize cobalamins: synthesis of homocysteinylcobalamin, N-acetylcysteinylcobalamin, 2-N-acetylamino-2-carbomethoxyethanethiolatocobalamin, sulfitocobalamin and nitrocobalamin. Dalton Trans 2006:5269-77. [PMID: 17088966 PMCID: PMC2754772 DOI: 10.1039/b610158e] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Glutathionylcobalamin, nitrocobalamin and sulfitocobalamin are important cobalamin metabolites isolable from human tissues. Herein we demonstrate that a procedure used to synthesize and isolate gamma-glutamylcysteinylcobalamin and glutathionylcobalamin in aqueous solution in high yield and purity can be used to synthesize other novel, biologically relevant thiolatocobalamins, including d,l-homocysteinylcobalamin, N-acetyl-l-cysteinylcobalamin (Na(+) salt) and 2-N-acetylamino-2-carbomethoxy-l-ethanethiolatocobalamin, as well as other non-alkylcobalamins, such as sulfitocobalamin (Na(+) salt) and nitrocobalamin. This uncomplicated, general procedure will assist researchers in identifying unknown cobalamin metabolites isolated from biological samples, and researchers interested in studying the uptake and intracellular cobalamin processing mechanisms utilizing non-alkylcobalamin derivatives that are not yet commercially available. The X-ray structure and XAS spectrum of N-acetyl-l-cysteinylcobalamin are also presented.
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Depeint F, Bruce WR, Shangari N, Mehta R, O’Brien PJ. Mitochondrial function and toxicity: Role of B vitamins on the one-carbon transfer pathways. Chem Biol Interact 2006; 163:113-32. [DOI: 10.1016/j.cbi.2006.05.010] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Revised: 05/17/2006] [Accepted: 05/18/2006] [Indexed: 02/05/2023]
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121
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Peters TJ, Kotowicz J, Nyka W, Kozubski W, Kuznetsov V, Vanderbist F, de Niet S, Marcereuil D, Coffiner M. TREATMENT OF ALCOHOLIC POLYNEUROPATHY WITH VITAMIN B COMPLEX: A RANDOMISED CONTROLLED TRIAL. Alcohol Alcohol 2006; 41:636-42. [PMID: 16926172 DOI: 10.1093/alcalc/agl058] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS To evaluate the therapeutic efficacy and safety of BEFACT Forte 'new formulation' and BEFACT Forte 'old formulation' in the treatment of sensory symptoms of alcoholic polyneuropathy. METHODS A multi-centre, randomised, double-blind, placebo-controlled study was conducted on 325 patients with sensory symptoms and signs of alcoholic polyneuropathy. Patients were randomised to the 'old formulation' (i.e. vitamins B1, B2, B6, and B12), 'new formulation' [i.e. identical to the 'old formulation' with additional folic acid (vitamin B9)], or placebo in a 1:1:1 ratio. One tablet of the study medication ('new formulation' or 'old formulation') or placebo was taken orally, three times a day, over a 12-week treatment period. RESULTS Therapeutic efficacy was assessed in 253 patients by measuring vibration perception threshold (biothesiometry), intensity of pain, sensory function, co-ordination, and reflex responses. Patients treated with the 'new formulation' or 'old formulation' showed significant improvement in the primary efficacy endpoint (vibration perception threshold at the big toe) and secondary efficacy endpoints in comparison to placebo. The active treatment groups were comparable to placebo in terms of safety. CONCLUSIONS A specific vitamin B complex (with and without folic acid) significantly improved symptoms of alcoholic polyneuropathy over a 12-week treatment period.
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Affiliation(s)
- T J Peters
- Department of Clinical Biochemistry, Kings College, Denmark Hill, London, UK.
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Affiliation(s)
- Perry A Frey
- Department of Biochemistry, University of Wisconsin-Madison, 1710 University Avenue, Madison, Wisconsin 53726, USA
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123
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Abstract
Many coenzymes are vitamins that are assimilated in mammals into their active form from precursors obtained from the diet. They are often both rare and reactive rendering the likelihood low that the cell uses a collision-based strategy for their delivery to dependent enzymes. In humans, there are only two known B12 or cobalamin-dependent enzymes: methionine synthase and methylmalonyl-CoA mutase. However, the pathway for intracellular assimilation and utilization of this cofactor is complex as revealed by careful clinical analyses of fibroblasts from patients with disorders of cobalamin metabolism. In the recent past, six of the eight human genes involved in the B12 pathway have been identified and these have yielded important insights into their roles. The recent literature on the encoded proteins is reviewed, and a model for intracellular B12 trafficking is proposed in which B12 is escorted to its target proteins in the cytoplasmic and mitochondrial compartments in complex with chaperones, thereby averting problems of dilution and adventitious side reactions.
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Affiliation(s)
- Ruma Banerjee
- Redox Biology Center and the Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0664, USA.
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