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Maiorova LA, Gromova OA, Torshin IY, Bukreeva TV, Pallaeva TN, Nabatov BV, Dereven'kov IA, Bobrov YA, Bykov AA, Demidov VI, Kalacheva AG, Bogacheva TE, Grishina TR, Nikolskaya ED, Yabbarov NG. Nanoparticles of nucleotide-free analogue of vitamin B 12 formed in protein nanocarriers and their neuroprotective activity in vivo. Colloids Surf B Biointerfaces 2024; 244:114165. [PMID: 39217725 DOI: 10.1016/j.colsurfb.2024.114165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 08/16/2024] [Accepted: 08/17/2024] [Indexed: 09/04/2024]
Abstract
Recently, we have described the first supermolecular nanoentities of vitamin B12 derivative, viz. monocyano form of heptabutyl cobyrinate, unique nanoparticles with strong noncovalent intermolecular interactions, emerging optical and catalytic properties. Their nearest analogue, heptamethyl cobyrinate (ACCby), exhibits bioactivity. Here, we demonstrate the first example of the formation of nanoparticles of this nucleotide-free analogue of vitamin B12 in protein nanocarriers and neuroprotective activity in vivo of the own nanoform of the drug. The preparation and characterization of nanocarriers based on bovine serum albumin (BSA) loaded with vitamin B12 (viz. cyano- and aquacobalamins) and ACCby were performed. Nucleotide-free analogue of vitamin B12 is tightly retained by the protein structure and exists in an incorporated state in the form of nanoparticles. The effect of encapsulated drugs on the character and severity of primary generalized seizures in rats induced by the pharmacotoxicant thiosemicarbazide was studied. Cyanocobalamin and ACCby exhibited a neuroprotective effect. The best influence of the encapsulation on the effectiveness of the drugs was achieved in the case of AСCby, whose bioavailability as a neuroprotector did not change upon introduction in BSA particles, i.e., 33 % of surviving animals were observed upon ACCby administration in free form and in encapsulated state. No surviving rats were observed without the administration of drugs. Thus, BSA nanocarriers loaded by nanoparticles of nucleotide-free analogues of vitamin B12, including hydrophobic ones, can be recommended for neuroprotection and targeted delivery.
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Affiliation(s)
- Larissa A Maiorova
- Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Ivanovo, Russia; Federal Research Center Computer Science and Control of Russian Academy of Sciences, Moscow, Russia.
| | - Olga A Gromova
- Federal Research Center Computer Science and Control of Russian Academy of Sciences, Moscow, Russia
| | - Ivan Yu Torshin
- Federal Research Center Computer Science and Control of Russian Academy of Sciences, Moscow, Russia
| | - Tatiana V Bukreeva
- Kurchatov Complex Crystallography and Photonics, National Research Centre "Kurchatov Institute", Moscow, Russia
| | - Tatiana N Pallaeva
- Kurchatov Complex Crystallography and Photonics, National Research Centre "Kurchatov Institute", Moscow, Russia
| | - Boris V Nabatov
- Kurchatov Complex Crystallography and Photonics, National Research Centre "Kurchatov Institute", Moscow, Russia
| | - Ilia A Dereven'kov
- Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Ivanovo, Russia
| | | | | | - Vadim I Demidov
- Ivanovo State Medical University, Ministry of Health of Russia, Ivanovo, Russia
| | - Alla G Kalacheva
- Ivanovo State Medical University, Ministry of Health of Russia, Ivanovo, Russia
| | - Tatiana E Bogacheva
- Ivanovo State Medical University, Ministry of Health of Russia, Ivanovo, Russia
| | - Tatiana R Grishina
- Ivanovo State Medical University, Ministry of Health of Russia, Ivanovo, Russia
| | - Elena D Nikolskaya
- N.M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 4 Kosygina Street, Moscow, Russia
| | - Nikita G Yabbarov
- N.M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 4 Kosygina Street, Moscow, Russia
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2
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Ruetz M, Mascarenhas R, Widner F, Kieninger C, Koutmos M, Kräutler B, Banerjee R. A Noble Metal Substitution Leads to B 12 Cofactor Mimicry by a Rhodibalamin. Biochemistry 2024; 63:1955-1962. [PMID: 39012171 DOI: 10.1021/acs.biochem.4c00216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
In mammals, cobalamin is an essential cofactor that is delivered by a multitude of chaperones in an elaborate trafficking pathway to two client enzymes, methionine synthase and methylmalonyl-CoA mutase (MMUT). Rhodibalamins, the rhodium analogs of cobalamins, have been described as antimetabolites due to their ability to inhibit bacterial growth. In this study, we have examined the reactivity of adenosylrhodibalamin (AdoRhbl) with two key human chaperones, MMACHC (also known as CblC) and adenosyltransferase (MMAB, also known as ATR), and with the human and Mycobacterium tuberculosis MMUT. We demonstrate that while AdoRhbl binds tightly to all four proteins, the Rh-carbon bond is resistant to homolytic (on MMAB and MMUT) as well as heterolytic (on MMACHC) rupture. On the other hand, MMAB catalyzes Rh-carbon bond formation, converting rhodi(I)balamin in the presence of ATP to AdoRhbl. We report the first crystal structure of a rhodibalamin (AdoRhbl) bound to a B12 protein, i.e., MMAB, in the presence of triphosphate, which shows a weakened but intact Rh-carbon bond. The structure provides insights into how MMAB cleaves the corresponding Co-carbon bond in a sacrificial homolytic reaction that purportedly functions as a cofactor sequestration strategy. Collectively, the study demonstrates that while the noble metal substitution of cobalt by rhodium sets up structural mimicry, it compromises chemistry, which could be exploited for targeting human and bacterial B12 chaperones and enzymes.
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3
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Domínguez-López I, Kovatcheva M, Casas R, Toledo E, Fitó M, Ros E, Estruch R, Serrano M, Lamuela-Raventós RM. Higher circulating vitamin B12 is associated with lower levels of inflammatory markers in individuals at high cardiovascular risk and in naturally aged mice. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:875-882. [PMID: 37690097 DOI: 10.1002/jsfa.12976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 09/12/2023]
Abstract
BACKGROUND Vitamin B12 is an essential nutrient that is involved in numerous physiological processes, and its deficiency can lead to various complications, including neurological and haematological disorders. Some studies have suggested that vitamin B12 may have anti-inflammatory effects, but the mechanisms underlying this relationship are not yet fully understood. We investigated the relationship between circulating vitamin B12 and inflammatory markers interleukin (IL)-6 and C-reactive protein (CRP). The association of peripheral levels of vitamin B12 with IL-6 and CRP was assessed in 136 human samples from a high cardiovascular risk population. To corroborate the results from the human trial, the analysis was replicated in naturally aged mice. RESULTS Individuals with higher serum levels of vitamin B12 showed lower concentrations of IL-6 and CRP after adjustment for potential confounders, and an inverse association was also found between serum IL-6 and vitamin B12 levels in naturally aged mice. CONCLUSION Circulating vitamin B12 was inversely associated with IL-6 and CRP in humans and with IL-6 in mice, suggesting that it may exert an anti-inflammatory effect through modulation of these pro-inflammatory molecules. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Inés Domínguez-López
- Departament de Nutrició, Ciències de l'Alimentació i Gastronomia, Facultat de Farmacia, Universitat de Barcelon (UB), Barcelona, Spain
- Institut de Nutrició i Seguretat Alimentària (INSA), Universitat de Barcelona (UB), Santa Coloma de Gramanet, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Kovatcheva
- Institute for Research in Biomedicine (IRB), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Rosa Casas
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- Department of Internal Medicine, Hospital Clinic, Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Estefanía Toledo
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- Department of Preventive Medicine and Public Health, University of Navarra, IdiSNA, Pamplona, Spain
| | - Montserrat Fitó
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- Unit of Cardiovascular Risk and Nutrition, Institut Hospital del Mar de Investigaciones Médicas (IMIM), Barcelona, Spain
| | - Emilio Ros
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- Department of Endocrinology, Hospital Clinic, IDIBAPS, Barcelona, Spain
| | - Ramon Estruch
- Institut de Nutrició i Seguretat Alimentària (INSA), Universitat de Barcelona (UB), Santa Coloma de Gramanet, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- Department of Internal Medicine, Hospital Clinic, Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain
| | - Manuel Serrano
- Institute for Research in Biomedicine (IRB), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Cambridge Institute of Science, Altos Labs, Cambridge, UK
| | - Rosa M Lamuela-Raventós
- Departament de Nutrició, Ciències de l'Alimentació i Gastronomia, Facultat de Farmacia, Universitat de Barcelon (UB), Barcelona, Spain
- Institut de Nutrició i Seguretat Alimentària (INSA), Universitat de Barcelona (UB), Santa Coloma de Gramanet, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
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Mascarenhas R, Guha A, Li Z, Ruetz M, An S, Seravalli J, Banerjee R. Cobalt-Sulfur Coordination Chemistry Drives B 12 Loading onto Methionine Synthase. J Am Chem Soc 2023:10.1021/jacs.3c07941. [PMID: 37916782 PMCID: PMC11063128 DOI: 10.1021/jacs.3c07941] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Cobalt-sulfur (Co-S) coordination is labile to both oxidation and reduction chemistry and is rarely seen in nature. Cobalamin (or vitamin B12) is an essential cobalt-containing organometallic cofactor in mammals and is escorted via an intricate network of chaperones to a single cytoplasmic target, methionine synthase. In this study, we report that the human cobalamin trafficking protein, MMADHC, exploits the chemical lability of Co-S coordination for cofactor off-loading onto methionine synthase. Cys-261 on MMADHC serves as the β-axial ligand to cobalamin. Complex formation between MMADHC and methionine synthase is signaled by loss of the lower axial nitrogen ligand, leading to five-coordinate thiolato-cobalamin. Nucleophilic displacement by the vicinal thiolate, Cys-262, completes cofactor transfer to methionine synthase and release of a cysteine disulfide-containing MMADHC. The physiological relevance of this mechanism is supported by clinical variants of MMADHC, which impair cofactor binding and off-loading, explaining the molecular basis of the associated homocystinuria.
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Affiliation(s)
- Romila Mascarenhas
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Arkajit Guha
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Zhu Li
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Markus Ruetz
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Sojin An
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Javier Seravalli
- Department of Biological Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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5
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Mascarenhas R, Guha A, Li Z, Ruetz M, An S, Seravalli J, Banerjee R. Cobalt-sulfur coordination chemistry drives B 12 loading onto methionine synthase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.25.550549. [PMID: 37546824 PMCID: PMC10402061 DOI: 10.1101/2023.07.25.550549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Cobalt-sulfur (Co-S) coordination is labile to both oxidation and reduction chemistry and is rarely seen in Nature. Cobalamin (or vitamin B 12 ) is an essential cobalt-containing organometallic cofactor in mammals, and is escorted via an intricate network of chaperones to a single cytoplasmic target, methionine synthase. In this study, we report that the human cobalamin trafficking protein, MMADHC, exploits the chemical lability of Co-S coordination, for cofactor off-loading onto methionine synthase. Cys-261 on MMADHC serves as the β-axial ligand to cobalamin. Complex formation between MMADHC and methionine synthase is signaled by loss of the lower axial nitrogen ligand, leading to five-coordinate thiolato-cobalamin. Nucleophilic displacement by the vicinal thiolate, Cys-262, completes cofactor transfer to methionine synthase and release of a cysteine disulfide-containing MMADHC. The physiological relevance of this mechanism is supported by clinical variants of MMADHC, which impair cofactor binding and off-loading, explaining the molecular basis of the associated homocystinuria.
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6
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Marques HM. The inorganic chemistry of the cobalt corrinoids - an update. J Inorg Biochem 2023; 242:112154. [PMID: 36871417 DOI: 10.1016/j.jinorgbio.2023.112154] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 01/23/2023] [Accepted: 01/26/2023] [Indexed: 02/05/2023]
Abstract
The inorganic chemistry of the cobalt corrinoids, derivatives of vitamin B12, is reviewed, with particular emphasis on equilibrium constants for, and kinetics of, their axial ligand substitution reactions. The role the corrin ligand plays in controlling and modifying the properties of the metal ion is emphasised. Other aspects of the chemistry of these compounds, including their structure, corrinoid complexes with metals other than cobalt, the redox chemistry of the cobalt corrinoids and their chemical redox reactions, and their photochemistry are discussed. Their role as catalysts in non-biological reactions and aspects of their organometallic chemistry are briefly mentioned. Particular mention is made of the role that computational methods - and especially DFT calculations - have played in developing our understanding of the inorganic chemistry of these compounds. A brief overview of the biological chemistry of the B12-dependent enzymes is also given for the reader's convenience.
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Affiliation(s)
- Helder M Marques
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa.
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7
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Toresson L, Suchodolski JS, Spillmann T, Lopes BC, Shih J, Steiner JM, Pilla R. The Intestinal Microbiome in Dogs with Chronic Enteropathies and Cobalamin Deficiency or Normocobalaminemia-A Comparative Study. Animals (Basel) 2023; 13:ani13081378. [PMID: 37106941 PMCID: PMC10135184 DOI: 10.3390/ani13081378] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 03/22/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Cobalamin deficiency is a common sequela of chronic enteropathies (CE) in dogs. Studies comparing the intestinal microbiome of CE dogs with cobalamin deficiency to those that are normocobalaminemic are lacking. Therefore, our aim was to describe the fecal microbiome in a prospective, comparative study evaluating 29 dogs with CE and cobalamin deficiency, 18 dogs with CE and normocobalaminemia, and 10 healthy control dogs. Dogs with cobalamin deficiency were also analyzed after oral or parenteral cobalamin supplementation. Overall microbiome composition (beta diversity) at baseline was significantly different in CE dogs with cobalamin deficiency when compared to those with normocobalaminemia (p = 0.001, R = 0.257) and to healthy controls (p = 0.001, R = 0.363). Abundances of Firmicutes and Actinobacteria were significantly increased (q = 0.010 and 0.049), while those of Bacteroidetes and Fusobacteria were significantly decreased (q = 0.002 and 0.014) in CE dogs with cobalamin deficiency when compared to healthy controls. Overall microbiome composition in follow-up samples remained significantly different after 3 months in both dogs receiving parenteral (R = 0.420, p = 0.013) or oral cobalamin supplementation (R = 0.251, p = 0.007). Because cobalamin supplementation, in combination with appropriate therapy, failed to restore the microbiome composition in the dogs in our study, cobalamin is unlikely to be the cause of those microbiome changes but rather an indicator of differences in underlying pathophysiology that do not influence clinical severity but result in a significant aggravation of dysbiosis.
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Affiliation(s)
- Linda Toresson
- Evidensia Specialist Animal Hospital Helsingborg, 254 66 Helsingborg, Sweden
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, 00014 Helsinki, Finland
| | - Jan S Suchodolski
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, 4474 TAMU, College Station, TX 77843-4474, USA
| | - Thomas Spillmann
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, 00014 Helsinki, Finland
| | - Bruna C Lopes
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, 4474 TAMU, College Station, TX 77843-4474, USA
| | - Johnathan Shih
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, 4474 TAMU, College Station, TX 77843-4474, USA
| | - Jörg M Steiner
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, 4474 TAMU, College Station, TX 77843-4474, USA
| | - Rachel Pilla
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, 4474 TAMU, College Station, TX 77843-4474, USA
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Temova Rakuša Ž, Roškar R, Hickey N, Geremia S. Vitamin B 12 in Foods, Food Supplements, and Medicines-A Review of Its Role and Properties with a Focus on Its Stability. MOLECULES (BASEL, SWITZERLAND) 2022; 28:molecules28010240. [PMID: 36615431 PMCID: PMC9822362 DOI: 10.3390/molecules28010240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022]
Abstract
Vitamin B12, also known as the anti-pernicious anemia factor, is an essential micronutrient totally dependent on dietary sources that is commonly integrated with food supplements. Four vitamin B12 forms-cyanocobalamin, hydroxocobalamin, 5'-deoxyadenosylcobalamin, and methylcobalamin-are currently used for supplementation and, here, we provide an overview of their biochemical role, bioavailability, and efficacy in different dosage forms. Since the effective quantity of vitamin B12 depends on the stability of the different forms, we further provide a review of their main reactivity and stability under exposure to various environmental factors (e.g., temperature, pH, light) and the presence of some typical interacting compounds (oxidants, reductants, and other water-soluble vitamins). Further, we explore how the manufacturing process and storage affect B12 stability in foods, food supplements, and medicines and provide a summary of the data published to date on the content-related quality of vitamin B12 products on the market. We also provide an overview of the approaches toward their stabilization, including minimization of the destabilizing factors, addition of proper stabilizers, or application of some (innovative) technological processes that could be implemented and contribute to the production of high-quality vitamin B12 products.
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Affiliation(s)
| | - Robert Roškar
- Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Neal Hickey
- Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
| | - Silvano Geremia
- Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
- Correspondence:
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9
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Esser AJ, Mukherjee S, Dereven‘kov IA, Makarov SV, Jacobsen DW, Spiekerkoetter U, Hannibal L. Versatile Enzymology and Heterogeneous Phenotypes in Cobalamin Complementation Type C Disease. iScience 2022; 25:104981. [PMID: 36105582 PMCID: PMC9464900 DOI: 10.1016/j.isci.2022.104981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Nutritional deficiency and genetic errors that impair the transport, absorption, and utilization of vitamin B12 (B12) lead to hematological and neurological manifestations. The cblC disease (cobalamin complementation type C) is an autosomal recessive disorder caused by mutations and epi-mutations in the MMACHC gene and the most common inborn error of B12 metabolism. Pathogenic mutations in MMACHC disrupt enzymatic processing of B12, an indispensable step before micronutrient utilization by the two B12-dependent enzymes methionine synthase (MS) and methylmalonyl-CoA mutase (MUT). As a result, patients with cblC disease exhibit plasma elevation of homocysteine (Hcy, substrate of MS) and methylmalonic acid (MMA, degradation product of methylmalonyl-CoA, substrate of MUT). The cblC disorder manifests early in childhood or in late adulthood with heterogeneous multi-organ involvement. This review covers current knowledge on the cblC disease, structure–function relationships of the MMACHC protein, the genotypic and phenotypic spectra in humans, experimental disease models, and promising therapies.
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10
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Kiessling E, Peters F, Ebner LJ, Merolla L, Samardzija M, Baumgartner MR, Grimm C, Froese DS. HIF1 and DROSHA are involved in MMACHC repression in hypoxia. Biochim Biophys Acta Gen Subj 2022; 1866:130175. [DOI: 10.1016/j.bbagen.2022.130175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 05/03/2022] [Accepted: 05/23/2022] [Indexed: 11/25/2022]
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11
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Vaccaro FA, Drennan CL. The role of nucleoside triphosphate hydrolase metallochaperones in making metalloenzymes. Metallomics 2022; 14:6575898. [PMID: 35485745 PMCID: PMC9164220 DOI: 10.1093/mtomcs/mfac030] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 04/07/2022] [Indexed: 11/13/2022]
Abstract
Metalloenzymes catalyze a diverse set of challenging chemical reactions that are essential for life. These metalloenzymes rely on a wide range of metallocofactors, from single metal ions to complicated metallic clusters. Incorporation of metal ions and metallocofactors into apo-proteins often requires the assistance of proteins known as metallochaperones. Nucleoside triphosphate hydrolases (NTPases) are one important class of metallochaperones and are found widely distributed throughout the domains of life. These proteins use the binding and hydrolysis of nucleoside triphosphates, either adenosine triphosphate (ATP) or guanosine triphosphate (GTP), to carry out highly specific and regulated roles in the process of metalloenzyme maturation. Here, we review recent literature on NTPase metallochaperones and describe the current mechanistic proposals and available structural data. By using representative examples from each type of NTPase, we also illustrate the challenges in studying these complicated systems. We highlight open questions in the field and suggest future directions. This minireview is part of a special collection of articles in memory of Professor Deborah Zamble, a leader in the field of nickel biochemistry.
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Affiliation(s)
- Francesca A Vaccaro
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA
| | - Catherine L Drennan
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA.,Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA.,Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
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12
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Subirana MA, Riemschneider S, Hause G, Dobritzsch D, Schaumlöffel D, Herzberg M. High spatial resolution imaging of subcellular macro and trace element distribution during phagocytosis. Metallomics 2022; 14:6530650. [PMID: 35179212 DOI: 10.1093/mtomcs/mfac011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/10/2022] [Indexed: 11/13/2022]
Abstract
The bioavailability of trace elements in the course of evolution had an essential influence on the emergence of life itself. This is reflected in the co-evolution between eukaryotes and prokaryotes. In this study, the influence and cellular distribution of bioelements during phagocytosis at the host-pathogen interface was investigated using high-resolution nanoscale secondary ion mass spectrometry (NanoSIMS) and quantitative inductively coupled plasma mass spectrometry (ICP-MS). In the eukaryotic murine macrophages (RAW 264.7 cell line), the cellular Fe / Zn ratio was found to be balanced, whereas the dominance of iron in the prokaryotic cells of the pathogen Salmonella enterica Serovar Enteritidis was about 90% compared to zinc. This confirms the evolutionary increased zinc requirement of the eukaryotic animal cell. Using NanoSIMS, the Cs+ primary ion source allowed high spatial resolution mapping of cell morphology down to subcellular level. At a comparable resolution, several low abundant trace elements could be mapped during phagocytosis with a RF plasma O- primary ion source. An enrichment of copper and nickel could be detected in the prokaryotic cells. Surprisingly, an accumulation of cobalt in the area of nuclear envelope was observed indicating an interesting but still unknown distribution of this trace element in murine macrophages.
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Affiliation(s)
- Maria Angels Subirana
- CNRS, Université de Pau et des Pays de l'Adour, E2S UPPA, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), UMR 5254, 64000 Pau, France
| | - Sina Riemschneider
- Fraunhofer Institute for Cell Therapy and Immunology (IZI), 04103 Leipzig, Germany
| | - Gerd Hause
- Martin-Luther-University Halle-Wittenberg, Biozentrum, Weinbergweg 22, 06120 Halle (Saale), Germany
| | - Dirk Dobritzsch
- Martin-Luther-University Halle-Wittenberg, Core Facility - Proteomic Mass Spectrometry, Kurt-Mothes-Str. 3a, 06120 Halle (Saale), Germany
| | - Dirk Schaumlöffel
- CNRS, Université de Pau et des Pays de l'Adour, E2S UPPA, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), UMR 5254, 64000 Pau, France.,Peoples' Friendship University of Russia (RUDN University), Mklukho-Maklaya str. 6, 117198 Moscow, Russia
| | - Martin Herzberg
- Martin-Luther-University Halle-Wittenberg, Institute for Biology/Microbiology, Kurt-Mothes-Str. 3, 06120 Halle/Saale, Germany
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13
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Engelbrecht M, Botha WJ, Pazzi P, McClure V, Hooijberg E. Serum cobalamin concentrations in dogs infected with canine parvoviral enteritis. J Am Vet Med Assoc 2022; 260:1-8. [PMID: 35113794 DOI: 10.2460/javma.21.05.0240] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare the serum cobalamin concentrations in canine parvovirus (CPV)-infected dogs with those of healthy control dogs. Animals 45 dogs with CPV enteritis and 17 healthy age-matched control dogs. Procedures Infection was confirmed by visualization of CPV-2 through fecal electron microscopy. All dogs received supportive care. Serum samples taken at admission were used to determine cobalamin, C-reactive protein, and albumin concentrations. Results Serum cobalamin concentrations were significantly lower in the CPV-infected group (median [interquartile range], 173 pmol/L [< 111 to 722 pmol/L]) than in healthy control dogs (379 pmol/L [193 to > 738 pmol/L). There was no association between cobalamin concentration and C-reactive protein or albumin concentration. Clinical Relevance While hypocobalaminemia was common in CPV-infected dogs, the clinical relevance of this finding remains to be determined. Studies assessing markers of cellular cobalamin deficiency in dogs with CPV infection appear warranted.
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Affiliation(s)
- Monique Engelbrecht
- Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | | | - Paolo Pazzi
- Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Vanessa McClure
- Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Emma Hooijberg
- Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
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14
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Mascarenhas R, Gouda H, Ruetz M, Banerjee R. Human B 12-dependent enzymes: Methionine synthase and Methylmalonyl-CoA mutase. Methods Enzymol 2022; 668:309-326. [PMID: 35589199 PMCID: PMC9420401 DOI: 10.1016/bs.mie.2021.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Humans have only two known cobalamin or B12-dependent enzymes: cytoplasmic methionine synthase and mitochondrial methylmalonyl-CoA mutase. A complex intracellular B12 trafficking pathway, comprising a multitude of chaperones, process and deliver cobalamin to the two target enzymes. Methionine synthase catalyzes the transfer of a methyl group from N5-methytetrahydrofolate to homocysteine, generating tetrahydrofolate and methionine. Cobalamin serves as an intermediate methyl group carrier and cycles between methylcobalamin and cob(I)alamin. Methylmalonyl-CoA mutase uses the 5'-deoxyadenosylcobalamin form of the cofactor and catalyzes the 1,2 rearrangement of methylmalonyl-CoA to succinyl-CoA. Two chaperones, CblA (or MMAA) and CblB (or MMAB, also known as adenosyltransferase), serve the mutase and ensure that the fidelity of the cofactor loading and unloading processes is maintained. This chapter focuses on assays for purifying and measuring the activities of methionine synthase and methylmalonyl-CoA mutase.
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15
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Gouda H, Mascarenhas R, Pillay S, Ruetz M, Koutmos M, Banerjee R. Patient mutations in human ATP:cob(I)alamin adenosyltransferase differentially affect its catalytic versus chaperone functions. J Biol Chem 2021; 297:101373. [PMID: 34757128 PMCID: PMC8633584 DOI: 10.1016/j.jbc.2021.101373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 11/26/2022] Open
Abstract
Human ATP:cob(I)alamin adenosyltransferase (ATR) is a mitochondrial enzyme that catalyzes an adenosyl transfer to cob(I)alamin, synthesizing 5′-deoxyadenosylcobalamin (AdoCbl) or coenzyme B12. ATR is also a chaperone that escorts AdoCbl, transferring it to methylmalonyl-CoA mutase, which is important in propionate metabolism. Mutations in ATR lead to methylmalonic aciduria type B, an inborn error of B12 metabolism. Our previous studies have furnished insights into how ATR protein dynamics influence redox-linked cobalt coordination chemistry, controlling its catalytic versus chaperone functions. In this study, we have characterized three patient mutations at two conserved active site residues in human ATR, R190C/H, and E193K and obtained crystal structures of R190C and E193K variants, which display only subtle structural changes. All three mutations were found to weaken affinities for the cob(II)alamin substrate and the AdoCbl product and increase KM(ATP). 31P NMR studies show that binding of the triphosphate product, formed during the adenosylation reaction, is also weakened. However, although the kcat of this reaction is significantly diminished for the R190C/H mutants, it is comparable with the WT enzyme for the E193K variant, revealing the catalytic importance of Arg-190. Furthermore, although the E193K mutation selectively impairs the chaperone function by promoting product release into solution, its catalytic function might be unaffected at physiological ATP concentrations. In contrast, the R190C/H mutations affect both the catalytic and chaperoning activities of ATR. Because the E193K mutation spares the catalytic activity of ATR, our data suggest that the patients carrying this mutation are more likely to be responsive to cobalamin therapy.
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Affiliation(s)
- Harsha Gouda
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Romila Mascarenhas
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Shubhadra Pillay
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Markus Ruetz
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Markos Koutmos
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA; Department of Biophysics, University of Michigan, Ann Arbor, Michigan, USA
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA.
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16
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Dereven’kov IA, Ugodin KA, Makarov SV. Mechanism of the Reaction between Cyanocobalamin and Reduced Flavin Mononucleotide. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2021. [DOI: 10.1134/s003602442110006x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Dereven'kov IA, Osokin VS, Hannibal L, Makarov SV, Khodov IA, Koifman OI. Mechanism of cyanocobalamin chlorination by hypochlorous acid. J Biol Inorg Chem 2021; 26:427-434. [PMID: 33914169 DOI: 10.1007/s00775-021-01869-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 04/22/2021] [Indexed: 11/29/2022]
Abstract
Hypochlorous acid (HOCl) is a strong oxidant produced by myeloperoxidase. Previous work suggested that HOCl modifies the corrin ring of cobalamins to yield chlorinated species via mechanisms that are incompletely understood. Herein, we report a mechanistic study on the reaction between cyanocobalamin (CNCbl, vitamin B12) and HOCl. Under weakly acidic, neutral and weakly alkaline conditions, the reaction produces the c-lactone derivative of CNCbl chlorinated at the C10-position of corrin ring (C10-Cl-CNCbl-c-lactone). Formation of C10-Cl-CNCbl-c-lactone was not observed at pH ≥ 9.9. The chlorination of CNCbl by HOCl proceeds via two pathways involving one and two HOCl molecules: the reaction is initiated by the very fast formation of a complex between CNCbl and HOCl, which either undergoes slow transformation to chlorinated species, or rapidly reacts with a second HOCl molecule to produce C10-Cl-CNCbl. Subsequent reaction of C10-Cl-CNCbl with HOCl proceeds rapidly toward lactone ring formation by H-atom abstraction at position C8. This work uncovered mechanisms and products of the reaction of a biologically active and therapeutically used cobalamin, CNCbl and the endogenous oxidant HOCl. Binding and reactivity studies of C10-Cl-CNCbl and C10-Cl-CNCbl-c-lactone with relevant proteins of the cobalamin pathway and with cultured cells are necessary to elucidate the potential physiological effects of these species.
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Affiliation(s)
- Ilia A Dereven'kov
- Ivanovo State University of Chemistry and Technology, Sheremetevskiy Str. 7, 153000, Ivanovo, Russian Federation.
| | - Vladimir S Osokin
- Ivanovo State University of Chemistry and Technology, Sheremetevskiy Str. 7, 153000, Ivanovo, Russian Federation
| | - Luciana Hannibal
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center-University of Freiburg, 79106, Freiburg, Germany
| | - Sergei V Makarov
- Ivanovo State University of Chemistry and Technology, Sheremetevskiy Str. 7, 153000, Ivanovo, Russian Federation
| | - Ilya A Khodov
- G.A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Akademicheskaya Str. 1, 153045, Ivanovo, Russian Federation
| | - Oskar I Koifman
- Ivanovo State University of Chemistry and Technology, Sheremetevskiy Str. 7, 153000, Ivanovo, Russian Federation
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18
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Banerjee R, Gouda H, Pillay S. Redox-Linked Coordination Chemistry Directs Vitamin B 12 Trafficking. Acc Chem Res 2021; 54:2003-2013. [PMID: 33797888 DOI: 10.1021/acs.accounts.1c00083] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Metals are partners for an estimated one-third of the proteome and vary in complexity from mononuclear centers to organometallic cofactors. Vitamin B12 or cobalamin represents the epitome of this complexity and is the product of an assembly line comprising some 30 enzymes. Unable to biosynthesize cobalamin, mammals rely on dietary provision of this essential cofactor, which is needed by just two enzymes, one each in the cytoplasm (methionine synthase) and the mitochondrion (methylmalonyl-CoA mutase). Brilliant clinical genetics studies on patients with inborn errors of cobalamin metabolism spanning several decades had identified at least seven genetic loci in addition to the two encoding B12 enzymes. While cells are known to house a cadre of chaperones dedicated to metal trafficking pathways that contain metal reactivity and confer targeting specificity, the seemingly supernumerary chaperones in the B12 pathway had raised obvious questions as to the rationale for their existence.With the discovery of the genes underlying cobalamin disorders, our laboratory has been at the forefront of ascribing functions to B12 chaperones and elucidating the intricate redox-linked coordination chemistry and protein-linked cofactor conformational dynamics that orchestrate the processing and translocation of cargo along the trafficking pathway. These studies have uncovered novel chemistry that exploits the innate chemical versatility of alkylcobalamins, i.e., the ability to form and dismantle the cobalt-carbon bond using homolytic or heterolytic chemistry. In addition, they have revealed the practical utility of the dimethylbenzimidazole tail, an appendage unique to cobalamins and absent in the structural cousins, porphyrin, chlorin, and corphin, as an instrument for facilitating cofactor transfer between active sites.In this Account, we navigate the chemistry of the B12 trafficking pathway from its point of entry into cells, through lysosomes, and into the cytoplasm, where incoming cobalamin derivatives with a diversity of upper ligands are denuded by the β-ligand transferase activity of CblC to the common cob(II)alamin intermediate. The broad reaction and lax substrate specificity of CblC also enables conversion of cyanocobalamin (technically, vitamin B12, i.e., the form of the cofactor in one-a-day supplements), to cob(II)alamin. CblD then hitches up with CblC via a unique Co-sulfur bond to cob(II)alamin at a bifurcation point, leading to the cytoplasmic methylcobalamin or mitochondrial 5'-deoxyadenosylcobalamin branch. Mutations at loci upstream of the junction point typically affect both branches, leading to homocystinuria and methylmalonic aciduria, whereas mutations in downstream loci lead to one or the other disease. Elucidation of the biochemical penalties associated with individual mutations is providing molecular insights into the clinical data and, in some instances, identifying which cobalamin derivative(s) might be therapeutically beneficial.Our studies on B12 trafficking are revealing strategies for cofactor sequestration and mobilization from low- to high-affinity and low- to high-coordination-number sites, which in turn are regulated by protein dynamics that constructs ergonomic cofactor binding pockets. While these B12 lessons might be broadly relevant to other metal trafficking pathways, much remains to be learned. This Account concludes by identifying some of the major gaps and challenges that are needed to complete our understanding of B12 trafficking.
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Affiliation(s)
- Ruma Banerjee
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Harsha Gouda
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Shubhadra Pillay
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
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19
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Mobile loop dynamics in adenosyltransferase control binding and reactivity of coenzyme B 12. Proc Natl Acad Sci U S A 2020; 117:30412-30422. [PMID: 33199623 DOI: 10.1073/pnas.2007332117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Cobalamin is a complex organometallic cofactor that is processed and targeted via a network of chaperones to its dependent enzymes. AdoCbl (5'-deoxyadenosylcobalamin) is synthesized from cob(II)alamin in a reductive adenosylation reaction catalyzed by adenosyltransferase (ATR), which also serves as an escort, delivering AdoCbl to methylmalonyl-CoA mutase (MCM). The mechanism by which ATR signals that its cofactor cargo is ready (AdoCbl) or not [cob(II)alamin] for transfer to MCM, is not known. In this study, we have obtained crystallographic snapshots that reveal ligand-induced ordering of the N terminus of Mycobacterium tuberculosis ATR, which organizes a dynamic cobalamin binding site and exerts exquisite control over coordination geometry, reactivity, and solvent accessibility. Cob(II)alamin binds with its dimethylbenzimidazole tail splayed into a side pocket and its corrin ring buried. The cosubstrate, ATP, enforces a four-coordinate cob(II)alamin geometry, facilitating the unfavorable reduction to cob(I)alamin. The binding mode for AdoCbl is notably different from that of cob(II)alamin, with the dimethylbenzimidazole tail tucked under the corrin ring, displacing the N terminus of ATR, which is disordered. In this solvent-exposed conformation, AdoCbl undergoes facile transfer to MCM. The importance of the tail in cofactor handover from ATR to MCM is revealed by the failure of 5'-deoxyadenosylcobinamide, lacking the tail, to transfer. In the absence of MCM, ATR induces a sacrificial cobalt-carbon bond homolysis reaction in an unusual reversal of the heterolytic chemistry that was deployed to make the same bond. The data support an important role for the dimethylbenzimidazole tail in moving the cobalamin cofactor between active sites.
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20
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Li Z, Greenhalgh ED, Twahir UT, Kallon A, Ruetz M, Warncke K, Brunold TC, Banerjee R. Chlorocob(II)alamin Formation Which Enhances the Thiol Oxidase Activity of the B 12-Trafficking Protein CblC. Inorg Chem 2020; 59:16065-16072. [PMID: 33074687 DOI: 10.1021/acs.inorgchem.0c02653] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CblC is a chaperone that catalyzes removal of the β-axial ligand of cobalamin (or B12), generating cob(II)alamin in an early step in the cofactor trafficking pathway. Cob(II)alamin is subsequently partitioned to support cellular needs for the synthesis of active cobalamin cofactor derivatives. In addition to the β-ligand transferase activity, the Caenorhabdiitis elegans CblC (ceCblC) and clinical R161G/Q variants of the human protein exhibit robust thiol oxidase activity, converting glutathione to glutathione disulfide while concomitantly reducing O2 to H2O2. The chemical efficiency of the thiol oxidase side reaction during ceCblC-catalyzed dealkylation of alkylcobalamins is noteworthy in that it effectively scrubs ambient oxygen from the reaction mixture, leading to air stabilization of the highly reactive cob(I)alamin product. In this study, we report that the enhanced thiol oxidase activity of ceCblC requires the presence of KCl, which explains how the wasteful thiol oxidase activity is potentially curtailed inside cells where the chloride concentration is low. We have captured an unusual chlorocob(II)alamin intermediate that is formed in the presence of potassium chloride, a common component of the reaction buffer, and have characterized it by electron paramagnetic resonance, magnetic circular dichroism, and computational analyses. The ability to form a chlorocob(II)alamin intermediate could represent an evolutionary vestige in ceCblC, which is structurally related to bacterial B12-dependent reductive dehalogenases that have been proposed to form halogen cob(II)alamin intermediates in their catalytic cycle.
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Affiliation(s)
- Zhu Li
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, United States
| | - Elizabeth D Greenhalgh
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Umar T Twahir
- Department of Physics, Emory University, Atlanta, Georgia 30322-2430, United States
| | - Albert Kallon
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, United States
| | - Markus Ruetz
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, United States
| | - Kurt Warncke
- Department of Physics, Emory University, Atlanta, Georgia 30322-2430, United States
| | - Thomas C Brunold
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, United States
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21
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Li Z, Mascarenhas R, Twahir UT, Kallon A, Deb A, Yaw M, Penner-Hahn J, Koutmos M, Warncke K, Banerjee R. An Interprotein Co-S Coordination Complex in the B 12-Trafficking Pathway. J Am Chem Soc 2020; 142:16334-16345. [PMID: 32871076 DOI: 10.1021/jacs.0c06590] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The CblC and CblD chaperones are involved in early steps in the cobalamin trafficking pathway. Cobalamin derivatives entering the cytoplasm are converted by CblC to a common cob(II)alamin intermediate via glutathione-dependent alkyltransferase or reductive elimination activities. Cob(II)alamin is subsequently converted to one of two biologically active alkylcobalamins by downstream chaperones. The function of CblD has been elusive although it is known to form a complex with CblC under certain conditions. Here, we report that CblD provides a sulfur ligand to cob(II)alamin bound to CblC, forming an interprotein coordination complex that rapidly oxidizes to thiolato-cob(III)alamin. Cysteine scanning mutagenesis and EPR spectroscopy identified Cys-261 on CblD as the sulfur donor. The unusual interprotein Co-S bond was characterized by X-ray absorption spectroscopy and visualized in the crystal structure of the human CblD thiolato-cob(III)alamin complex. Our study provides insights into how cobalamin coordination chemistry could be utilized for cofactor translocation in the trafficking pathway.
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Affiliation(s)
- Zhu Li
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, United States
| | - Romila Mascarenhas
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, United States
| | - Umar T Twahir
- Department of Physics, Emory University, Atlanta, Georgia 30322-2430, United States
| | - Albert Kallon
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, United States
| | - Aniruddha Deb
- Departments of Chemistry and Biophysics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Madeline Yaw
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, United States
| | - James Penner-Hahn
- Departments of Chemistry and Biophysics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Markos Koutmos
- Departments of Chemistry and Biophysics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Kurt Warncke
- Department of Physics, Emory University, Atlanta, Georgia 30322-2430, United States
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, United States
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22
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Gul M, Azari Jafari A, Shah M, Mirmoeeni S, Haider SU, Moinuddin S, Chaudhry A. Molecular Biomarkers in Multiple Sclerosis and Its Related Disorders: A Critical Review. Int J Mol Sci 2020; 21:E6020. [PMID: 32825639 PMCID: PMC7547375 DOI: 10.3390/ijms21176020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/10/2020] [Accepted: 08/14/2020] [Indexed: 12/17/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system (CNS) which can lead to severe disability. Several diseases can mimic the clinical manifestations of MS. This can often lead to a prolonged period that involves numerous tests and investigations before a definitive diagnosis is reached. As well as the possibility of misdiagnosis. Molecular biomarkers can play a unique role in this regard. Molecular biomarkers offer a unique view into the CNS disorders. They help us understand the pathophysiology of disease as well as guiding our diagnostic, therapeutic, and prognostic approaches in CNS disorders. This review highlights the most prominent molecular biomarkers found in the literature with respect to MS and its related disorders. Based on numerous recent clinical and experimental studies, we demonstrate that several molecular biomarkers could very well aid us in differentiating MS from its related disorders. The implications of this work will hopefully serve clinicians and researchers alike, who regularly deal with MS and its related disorders.
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Affiliation(s)
- Maryam Gul
- Precision Rheumatology INC, 2050 South Euclid Street, Anaheim, CA 92802, USA
| | - Amirhossein Azari Jafari
- Student Research Committee, School of Medicine, Shahroud University of Medical Sciences, Shahroud 3614773947, Iran; (A.A.J.); (S.M.)
| | - Muffaqam Shah
- Deccan College of Medical Sciences, P.O. Kanchanbagh, DMRL ‘X’ Road, Santhosh Nagar, Hyderabad 500058, Telangana State, India;
| | - Seyyedmohammadsadeq Mirmoeeni
- Student Research Committee, School of Medicine, Shahroud University of Medical Sciences, Shahroud 3614773947, Iran; (A.A.J.); (S.M.)
| | - Safee Ullah Haider
- Shaikh Khalifa Bin Zayed Al-Nahyan Medical College, Shaikh Zayed Medical Complex, Lahore 54000, Pakistan;
| | - Sadia Moinuddin
- Department of Internal Medicine, San Antonio Regional Medical Center, 999 San Bernardino Rd, Upland, CA 91786, USA;
| | - Ammar Chaudhry
- Department of Radiology, City of Hope National Medical Center, 1500 East Duarte Road, Duarte, CA 91010, USA;
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Mascarenhas R, Li Z, Gherasim C, Ruetz M, Banerjee R. The human B 12 trafficking protein CblC processes nitrocobalamin. J Biol Chem 2020; 295:9630-9640. [PMID: 32457044 DOI: 10.1074/jbc.ra120.014094] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/22/2020] [Indexed: 01/12/2023] Open
Abstract
In humans, cobalamin or vitamin B12 is delivered to two target enzymes via a complex intracellular trafficking pathway comprising transporters and chaperones. CblC (or MMACHC) is a processing chaperone that catalyzes an early step in this trafficking pathway. CblC removes the upper axial ligand of cobalamin derivatives, forming an intermediate in the pathway that is subsequently converted to the active cofactor derivatives. Mutations in the cblC gene lead to methylmalonic aciduria and homocystinuria. Here, we report that nitrosylcobalamin (NOCbl), which was developed as an antiproliferative reagent, and is purported to cause cell death by virtue of releasing nitric oxide, is highly unstable in air and is rapidly oxidized to nitrocobalamin (NO2Cbl). We demonstrate that CblC catalyzes the GSH-dependent denitration of NO2Cbl forming 5-coordinate cob(II)alamin, which had one of two fates. It could be oxidized to aquo-cob(III)alamin or enter a futile thiol oxidase cycle forming GSH disulfide. Arg-161 in the active site of CblC suppressed the NO2Cbl-dependent thiol oxidase activity, whereas the disease-associated R161G variant stabilized cob(II)alamin and promoted futile cycling. We also report that CblC exhibits nitrite reductase activity, converting cob(I)alamin and nitrite to NOCbl. Finally, the denitration activity of CblC supported cell proliferation in the presence of NO2Cbl, which can serve as a cobalamin source. The newly described nitrite reductase and denitration activities of CblC extend its catalytic versatility, adding to its known decyanation and dealkylation activities. In summary, upon exposure to air, NOCbl is rapidly converted to NO2Cbl, which is a substrate for the B12 trafficking enzyme CblC.
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Affiliation(s)
- Romila Mascarenhas
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Zhu Li
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Carmen Gherasim
- Department of Pathology, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Markus Ruetz
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan, USA
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Hu W, Li Q, Li B, Ma K, Zhang C, Fu X. Optogenetics sheds new light on tissue engineering and regenerative medicine. Biomaterials 2019; 227:119546. [PMID: 31655444 DOI: 10.1016/j.biomaterials.2019.119546] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 10/09/2019] [Accepted: 10/14/2019] [Indexed: 01/23/2023]
Abstract
Optogenetics has demonstrated great potential in the fields of tissue engineering and regenerative medicine, from basic research to clinical applications. Spatiotemporal encoding during individual development has been widely identified and is considered a novel strategy for regeneration. A as a noninvasive method with high spatiotemporal resolution, optogenetics are suitable for this strategy. In this review, we discuss roles of dynamic signal coding in cell physiology and embryonic development. Several optogenetic systems are introduced as ideal optogenetic tools, and their features are compared. In addition, potential applications of optogenetics for tissue engineering are discussed, including light-controlled genetic engineering and regulation of signaling pathways. Furthermore, we present how emerging biomaterials and photoelectric technologies have greatly promoted the clinical application of optogenetics and inspired new concepts for optically controlled therapies. Our summation of currently available data conclusively demonstrates that optogenetic tools are a promising method for elucidating and simulating developmental processes, thus providing vast prospects for tissue engineering and regenerative medicine applications.
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Affiliation(s)
- Wenzhi Hu
- Wound Healing and Cell Biology Laboratory, Institute of Basic Medicine Science, College of Life Science, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, PR China; Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China
| | - Qiankun Li
- Wound Healing and Cell Biology Laboratory, Institute of Basic Medicine Science, College of Life Science, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, PR China; Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China
| | - Bingmin Li
- Wound Healing and Cell Biology Laboratory, Institute of Basic Medicine Science, College of Life Science, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, PR China; Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China
| | - Kui Ma
- Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China
| | - Cuiping Zhang
- Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China.
| | - Xiaobing Fu
- Wound Healing and Cell Biology Laboratory, Institute of Basic Medicine Science, College of Life Science, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, PR China; Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China.
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25
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Pereira J, Simões M, Silva JL. Microalgal assimilation of vitamin B 12 toward the production of a superfood. J Food Biochem 2019; 43:e12911. [PMID: 31368540 DOI: 10.1111/jfbc.12911] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/07/2019] [Accepted: 05/08/2019] [Indexed: 12/24/2022]
Abstract
A network of components from different metabolic pathways is the building scaffold of an indispensable compound in the human organism-vitamin B12 . The biosynthesis of this compound is restricted to a limited number of representatives of bacteria and archaea, while vitamin B12 -dependent enzymes are spread through several domains of life. Different attempts have been performed to increase vitamin B12 levels in dietary products, particularly in vegetarian and vegan dietary regimes. The integration of vitamin B12 in microalgae through symbiosis with microorganisms generally recognized as safe, for example the probiotic Lactobacillus reuteri, can even increase the nutritional value of the microalgal biomass. This study reviews the microbial production of vitamin B12 based on genetic analyses and chemical studies. Recent genetic approaches are focused, particularly potential metabolic engineering targets to increase vitamin B12 production. The bioincorporation of vitamin B12 in microalgae as an attempt to provide a superfood is also reviewed. PRACTICAL APPLICATIONS: Novel food habits (i.e., vegan lifestyle) may lack relevant nutrients, including vitamin B12 . Therefore, there is an increased demand for dietary products rich in vitamin B12 . Of potential interest is the provision of microbial-based superfood rich in numerous nutrients, including this vitamin. This manuscript provides an in-depth and timely overview on vitamin B12 biosynthesis and the major advances on metabolic engineering for improved vitamin B12 production by probiotic bacteria and other microorganisms generally recognized as safe. A relevant advance would result from the bioincorporation of vitamin B12 in alternative microorganisms (non-vitamin B12 producers) increasingly recognized as superfood, that is microalgae.
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Affiliation(s)
- João Pereira
- Allmicroalgae-Natural Products, Lisboa, Portugal.,LEPABE, Departamento de Engenharia Química, da Universidade do Porto, Porto, Portugal
| | - Manuel Simões
- LEPABE, Departamento de Engenharia Química, da Universidade do Porto, Porto, Portugal
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26
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Toresson L, Steiner JM, Spodsberg E, Olmedal G, Suchodolski JS, Lidbury JA, Spillmann T. Effects of oral versus parenteral cobalamin supplementation on methylmalonic acid and homocysteine concentrations in dogs with chronic enteropathies and low cobalamin concentrations. Vet J 2018; 243:8-14. [PMID: 30606444 DOI: 10.1016/j.tvjl.2018.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 11/05/2018] [Accepted: 11/07/2018] [Indexed: 01/02/2023]
Abstract
The objective of this study was to compare the effects of parenteral (PE) versus oral (PO) cobalamin supplementation on serum methylmalonic acid (MMA) and homocysteine (HCY) concentrations in dogs with hypocobalaminaemia. Thirty-six dogs with serum cobalamin concentrations below 285ng/L (reference interval (RI): 244-959ng/L) were treated with PO (0.25-1.0mg daily) or PE cobalamin (0.25-1.2mg/injection) using a block-randomized schedule. Serum MMA and HCY concentrations were analysed at day 0, 28 and 90 after start of supplementation. There was no significant difference between the PO and PE group regarding serum MMA or HCY concentrations at any time point. Median (range, P comparing baseline and 28 days, P comparing 28days and 90 days) serum MMA concentrations (nmol/L; RI 415-1193) were 932 (566-2468) in the PO and 943 (508-1900) in the PE group at baseline, respectively, 705 (386-1465, P<0.0001) and 696 (377-932, P<0.0001) after 28 days, and 739 (450-1221, P=0.58) and 690 (349-1145, P=0.76) after 90 days. Serum HCY concentrations (median (range), P comparing baseline and 28 days, P comparing 28days and 90 days, μmol/L; RI 5.9-31.9) in the PO and PE groups were 12.2 (3.3-62.2) and 8.4 (3.7-34.8) at baseline, 12.5 (5.0-45.0, P=0.61) and 8.0 (3.8-18.3, P=0.28) after 28 days, and 17.7 (7.3-60.0 P=0.07) and 12.4 (6.3-33.1, P=0.0007) after 90 days, respectively. Oral and parenteral cobalamin supplementation had the same effect on serum MMA concentrations in this group of dogs.
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Affiliation(s)
- L Toresson
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, Agnes Sjobergin katu 2, 00014 Helsinki, Finland; Evidensia Specialist Animal Hospital, Bergavagen 3, 25466 Helsingborg, Sweden.
| | - J M Steiner
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, 4474 TAMU, College Station, TX 77843-4474, USA
| | - E Spodsberg
- Evidensia Specialist Animal Hospital, Bergavagen 3, 25466 Helsingborg, Sweden
| | - G Olmedal
- Evidensia Specialist Animal Hospital, Bergavagen 3, 25466 Helsingborg, Sweden
| | - J S Suchodolski
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, 4474 TAMU, College Station, TX 77843-4474, USA
| | - J A Lidbury
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, 4474 TAMU, College Station, TX 77843-4474, USA
| | - T Spillmann
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, Agnes Sjobergin katu 2, 00014 Helsinki, Finland
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27
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Salinas M, Flores E, López-Garrigós M, Leiva-Salinas C. Vitamin B12 deficiency and clinical laboratory: Lessons revisited and clarified in seven questions. Int J Lab Hematol 2018; 40 Suppl 1:83-88. [PMID: 29741251 DOI: 10.1111/ijlh.12833] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 03/22/2018] [Indexed: 11/26/2022]
Abstract
The objective of this review article is to address the most frequently asked questions that pathologists and primary care physicians might face when dealing with a patient with suspicion of vitamin B12 deficiency. More specifically, the article mainly discusses the importance and prevalence of the deficit, how to recognize it, and the important role of a prompt diagnosis confirmation based on laboratory biomarkers for efficient replacement therapy.
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Affiliation(s)
- M Salinas
- Clinical Laboratory, Hospital Universitario de San Juan, San Juan de Alicante, Spain.,Department of Biochemistry and Molecular Pathology, Universidad Miguel Hernandez, Elche, Spain
| | - E Flores
- Clinical Laboratory, Hospital Universitario de San Juan, San Juan de Alicante, Spain.,Department of Clinic Medicine, Universidad Miguel Hernandez, Elche, Spain
| | - M López-Garrigós
- Clinical Laboratory, Hospital Universitario de San Juan, San Juan de Alicante, Spain
| | - C Leiva-Salinas
- Department of Clinical Radiology, University of Missouri Health, Columbia, MO, USA
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28
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Brasil S, Leal F, Vega A, Navarrete R, Ecay MJ, Desviat LR, Riera C, Padilla N, de la Cruz X, Couce ML, Martin-Hernández E, Morais A, Pedrón C, Peña-Quintana L, Rigoldi M, Specola N, de Almeida IT, Vives I, Yahyaoui R, Rodríguez-Pombo P, Ugarte M, Pérez-Cerda C, Merinero B, Pérez B. Improving the diagnosis of cobalamin and related defects by genomic analysis, plus functional and structural assessment of novel variants. Orphanet J Rare Dis 2018; 13:125. [PMID: 30041674 PMCID: PMC6057060 DOI: 10.1186/s13023-018-0862-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 06/29/2018] [Indexed: 12/04/2022] Open
Abstract
Background Cellular cobalamin defects are a locus and allelic heterogeneous disorder. The gold standard for coming to genetic diagnoses of cobalamin defects has for some time been gene-by-gene Sanger sequencing of individual DNA fragments. Enzymatic and cellular methods are employed before such sequencing to help in the selection of the gene defects to be sought, but this is time-consuming and laborious. Furthermore some cases remain undiagnosed because no biochemical methods have been available to test for cobalamin absorption and transport defects. Results This paper reports the use of massive parallel sequencing of DNA (exome analysis) for the accurate and rapid genetic diagnosis of cobalamin-related defects in a cohort of affected patients. The method was first validated in an initial cohort with different cobalamin defects. Mendelian segregation, the frequency of mutations, and the comprehensive structural and functional analysis of gene variants, identified disease-causing mutations in 12 genes involved in the absorption and synthesis of active cofactors of vitamin B12 (22 cases), and in the non-cobalamin metabolism-related genes ACSF3 (in four biochemically misdiagnosed patients) and SUCLA2 (in one patient with an unusual presentation). We have identified thirteen new variants all classified as pathogenic according to the ACGM recommendation but four were classified as variant likely pathogenic in MUT and SUCLA2. Functional and structural analysis provided evidences to classify them as pathogenic variants. Conclusions The present findings suggest that the technology used is sufficiently sensitive and specific, and the results it provides sufficiently reproducible, to recommend its use as a second-tier test after the biochemical detection of cobalamin disorder markers in the first days of life. However, for accurate diagnoses to be made, biochemical and functional tests that allow comprehensive clinical phenotyping are also needed. Electronic supplementary material The online version of this article (10.1186/s13023-018-0862-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sandra Brasil
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Universidad Autónoma de Madrid, CIBERER, IdiPAZ, Madrid, Spain
| | - Fátima Leal
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Universidad Autónoma de Madrid, CIBERER, IdiPAZ, Madrid, Spain
| | - Ana Vega
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Universidad Autónoma de Madrid, CIBERER, IdiPAZ, Madrid, Spain
| | - Rosa Navarrete
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Universidad Autónoma de Madrid, CIBERER, IdiPAZ, Madrid, Spain
| | - María Jesús Ecay
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Universidad Autónoma de Madrid, CIBERER, IdiPAZ, Madrid, Spain
| | - Lourdes R Desviat
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Universidad Autónoma de Madrid, CIBERER, IdiPAZ, Madrid, Spain
| | - Casandra Riera
- Grupo de Bioinformática Translacional Vall d'Hebron Institute of Research (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Natàlia Padilla
- Grupo de Bioinformática Translacional Vall d'Hebron Institute of Research (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Xavier de la Cruz
- Grupo de Bioinformática Translacional Vall d'Hebron Institute of Research (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain.,ICREA, Barcelona, Spain
| | - Mari Luz Couce
- Hospital Clínico Universitario de Santiago, Santiago de Compostela, CIBERER, Santiago de Compostela, Spain
| | | | - Ana Morais
- Hospital Universitario La Paz, Madrid, Spain
| | | | - Luis Peña-Quintana
- Hospital Universitario Materno Infantil, CIBEROBN, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Miriam Rigoldi
- Center for Rare Disorders, ASST- Monza, Ospedale San Gerardo, Monza, Italy
| | - Norma Specola
- Unidad de Metabolismo Hospital de Niños de La Plata, La Plata, Argentina
| | | | | | - Raquel Yahyaoui
- Hospital Universitario Regional de Málaga, Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga, Spain
| | - Pilar Rodríguez-Pombo
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Universidad Autónoma de Madrid, CIBERER, IdiPAZ, Madrid, Spain
| | - Magdalena Ugarte
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Universidad Autónoma de Madrid, CIBERER, IdiPAZ, Madrid, Spain
| | - Celia Pérez-Cerda
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Universidad Autónoma de Madrid, CIBERER, IdiPAZ, Madrid, Spain
| | - Begoña Merinero
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Universidad Autónoma de Madrid, CIBERER, IdiPAZ, Madrid, Spain
| | - Belén Pérez
- Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular, Universidad Autónoma de Madrid, CIBERER, IdiPAZ, Madrid, Spain.
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29
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Hannibal L, Bolisetty K, Axhemi A, DiBello PM, Quadros EV, Fedosov S, Jacobsen DW. Transcellular transport of cobalamin in aortic endothelial cells. FASEB J 2018; 32:5506-5519. [PMID: 29741927 DOI: 10.1096/fj.201701141rr] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cobalamin [Cbl (or B12)] deficiency causes megaloblastic anemia and a variety of neuropathies. However, homeostatic mechanisms of cyanocobalamin (CNCbl) and other Cbls by vascular endothelial cells are poorly understood. Herein, we describe our investigation into whether cultured bovine aortic endothelial cells (BAECs) perform transcytosis of B12, namely, the complex formed between serum transcobalamin and B12, designated as holo-transcobalamin (holo-TC). We show that cultured BAECs endocytose [57Co]-CNCbl-TC (source material) via the CD320 receptor. The bound Cbl is transported across the cell both via exocytosis in its free form, [57Co]-CNCbl, and via transcytosis as [57Co]-CNCbl-TC. Transcellular mobilization of Cbl occurred in a bidirectional manner. A portion of the endocytosed [57Co]-CNCbl was enzymatically processed by methylmalonic aciduria combined with homocystinuria type C (cblC) with subsequent formation of hydroxocobalamin, methylcobalamin, and adenosylcobalamin, which were also transported across the cell in a bidirectional manner. This demonstrates that transport mechanisms for Cbl in vascular endothelial cells do not discriminate between various β-axial ligands of the vitamin. Competition studies with apoprotein- and holo-TC and holo-intrinsic factor showed that only holo-TC was effective at inhibiting transcellular transport of Cbl. Incubation of BAECs with a blocking antibody against the extracellular domain of the CD320 receptor inhibited uptake and transcytosis by ∼40%. This study reveals that endothelial cells recycle uncommitted intracellular Cbl for downstream usage by other cell types and suggests that the endothelium is self-sufficient for the specific acquisition and subsequent distribution of circulating B12 via the CD320 receptor. We posit that the endothelial lining of the vasculature is an essential component for the maintenance of serum-tissue homeostasis of B12.-Hannibal, L., Bolisetty, K., Axhemi, A., DiBello, P. M., Quadros, E. V., Fedosov, S., Jacobsen, D. W. Transcellular transport of cobalamin in aortic endothelial cells.
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Affiliation(s)
- Luciana Hannibal
- Laboratory of Clinical Biochemistry and Metabolism, Department for Pediatrics, Medical Center, University of Freiburg, Freiburg, Germany.,Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Keerthana Bolisetty
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Armend Axhemi
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Patricia M DiBello
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Edward V Quadros
- Department of Medicine, State University of New York (SUNY) Downstate Medical Center, Brooklyn, New York, USA; and
| | - Sergey Fedosov
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Donald W Jacobsen
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
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30
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Dereven'kov IA, Hannibal L, Makarov SV, Makarova AS, Molodtsov PA, Koifman OI. Characterization of the complex between native and reduced bovine serum albumin with aquacobalamin and evidence of dual tetrapyrrole binding. J Biol Inorg Chem 2018; 23:725-738. [PMID: 29721769 DOI: 10.1007/s00775-018-1562-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Accepted: 04/25/2018] [Indexed: 11/30/2022]
Abstract
Serum albumin binds to a variety of endogenous ligands and drugs. Human serum albumin (HSA) binds to heme via hydrophobic interactions and axial coordination of the iron center by protein residue Tyr161. Human serum albumin binds to another tetrapyrrole, cobalamin (Cbl), but the structural and functional properties of this complex are poorly understood. Herein, we investigate the reaction between aquacobalamin (H2OCbl) and bovine serum albumin (BSA, the bovine counterpart of HSA) using Ultraviolet-Visible and fluorescent spectroscopy, and electron paramagnetic resonance. The reaction between H2OCbl and BSA led to the formation of a BSA-Cbl(III) complex consistent with N-axial ligation (amino). Prior to the formation of this complex, the reactants participate in an additional binding event that has been examined by fluorescence spectroscopy. Binding of BSA to Cbl(III) reduced complex formation between the bound cobalamin and free cyanide to form cyanocobalamin (CNCbl), suggesting that the β-axial position of the cobalamin may be occupied by an amino acid residue from the protein. Reaction of BSA containing reduced disulfide bonds with H2OCbl produces cob(II)alamin and disulfide with intermediate formation of thiolate Cbl(III)-BSA complex and its decomposition. Finally, in vitro studies showed that cobalamin binds to BSA only in the presence of an excess of protein, which is in contrast to heme binding to BSA that involves a 1:1 stoichiometry. In vitro formation of BSA-Cbl(III) complex does not preclude subsequent heme binding, which occurs without displacement of H2OCbl bound to BSA. These data suggest that the two tetrapyrroles interact with BSA in different binding pockets.
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Affiliation(s)
- Ilia A Dereven'kov
- Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Sheremetevskiy Str. 7, Ivanovo, 153000, Russian Federation.
| | - Luciana Hannibal
- Laboratory of Clinical Biochemistry and Metabolism, Department for Pediatrics, Medical Center, University of Freiburg, Mathildenstr. 1, 79106, Freiburg, Germany
| | - Sergei V Makarov
- Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Sheremetevskiy Str. 7, Ivanovo, 153000, Russian Federation
| | - Anna S Makarova
- G. A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Academicheskaya Str 1, Ivanovo, 153045, Russian Federation
| | - Pavel A Molodtsov
- Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Sheremetevskiy Str. 7, Ivanovo, 153000, Russian Federation
| | - Oskar I Koifman
- Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Sheremetevskiy Str. 7, Ivanovo, 153000, Russian Federation
- G. A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Academicheskaya Str 1, Ivanovo, 153045, Russian Federation
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31
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Chan W, Almasieh M, Catrinescu MM, Levin LA. Cobalamin-Associated Superoxide Scavenging in Neuronal Cells Is a Potential Mechanism for Vitamin B 12-Deprivation Optic Neuropathy. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:160-172. [PMID: 29037851 PMCID: PMC5745528 DOI: 10.1016/j.ajpath.2017.08.032] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Revised: 07/31/2017] [Accepted: 08/28/2017] [Indexed: 12/16/2022]
Abstract
Chronic deficiency of vitamin B12 is the only nutritional deficiency definitively proved to cause optic neuropathy and loss of vision. The mechanism by which this occurs is unknown. Optic neuropathies are associated with death of retinal ganglion cells (RGCs), neurons that project their axons along the optic nerve to the brain. Injury to RGC axons causes a burst of intracellular superoxide, which then signals RGC apoptosis. Vitamin B12 (cobalamin) was recently shown to be a superoxide scavenger, with a rate constant similar to superoxide dismutase. Given that vitamin B12 deficiency causes an optic neuropathy through unknown mechanisms and that it is a potent superoxide scavenger, we tested whether cobalamin, a vitamin B12 vitamer, would be neuroprotective in vitro and in vivo. We found that cobalamin scavenged superoxide in neuronal cells in vitro treated with the reduction-oxidation cycling agent menadione. In vivo confocal scanning laser ophthalmoscopy demonstrated that optic nerve transection in Long-Evans rats increased superoxide levels in RGCs. The RGC superoxide burst was significantly reduced by intravitreal cobalamin and resulted in increased RGC survival. These data demonstrate that cobalamin may function as an endogenous neuroprotectant for RGCs through a superoxide-associated mechanism.
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Affiliation(s)
- Wesley Chan
- Maisonneuve-Rosemont Hospital Research Center and Department of Ophthalmology, University of Montreal, Montreal, Quebec, Canada
| | - Mohammadali Almasieh
- Maisonneuve-Rosemont Hospital Research Center and Department of Ophthalmology, University of Montreal, Montreal, Quebec, Canada; Department of Ophthalmology, McGill University, Montreal, Quebec, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Maria-Magdalena Catrinescu
- Maisonneuve-Rosemont Hospital Research Center and Department of Ophthalmology, University of Montreal, Montreal, Quebec, Canada; Department of Ophthalmology, McGill University, Montreal, Quebec, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Leonard A Levin
- Maisonneuve-Rosemont Hospital Research Center and Department of Ophthalmology, University of Montreal, Montreal, Quebec, Canada; Department of Ophthalmology, McGill University, Montreal, Quebec, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada; Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
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32
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Toresson L, Steiner JM, Razdan P, Spodsberg E, Olmedal G, Suchodolski JS, Spillmann T. Comparison of efficacy of oral and parenteral cobalamin supplementation in normalising low cobalamin concentrations in dogs: A randomised controlled study. Vet J 2017; 232:27-32. [PMID: 29428088 DOI: 10.1016/j.tvjl.2017.12.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 12/07/2017] [Accepted: 12/11/2017] [Indexed: 01/02/2023]
Abstract
The aim of this study was to compare the efficacies of parenteral and oral cobalamin supplementation protocols in dogs with chronic enteropathies and low cobalamin concentrations. It was hypothesised that both treatments would increase serum cobalamin concentrations significantly. Fifty-three dogs with chronic enteropathies and serum cobalamin concentrations<285ng/L (reference interval 244-959ng/L) were enrolled. Dogs were randomised to treatment with either daily oral cobalamin tablets (0.25-1.0mg cyanocobalamin daily according to body weight) or parenteral cobalamin (0.4-1.2mg hydroxycobalamin according to body weight). Serum cobalamin concentrations were analysed 28±5days and 90±15days after initiation of supplementation. After 28 days, all dogs had serum cobalamin concentrations within the reference interval or above. In the parenteral group (n=26), median (range) cobalamin concentrations were 228 (150-285) ng/L at inclusion, 2107 (725-10,009) ng/L after 28days and 877 (188-1267) ng/L after 90 days. In the oral group (n=27), median (range) serum cobalamin concentrations were 245 (150-285) ng/L at inclusion, 975 (564-2385) ng/L after 28days and 1244 (738-4999) ng/L after 90 days. In both groups, there were significant differences in serum cobalamin concentrations between baseline and 28 days, and between 28days and 90days (P<0.001). In conclusion, both parenteral and oral cobalamin supplementation effectively increase serum cobalamin concentrations in dogs with chronic enteropathies and low cobalamin concentrations.
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Affiliation(s)
- L Toresson
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, Agnes Sjobergin katu 2, 00014 Helsinki, Finland; Evidensia Specialist Animal Hospital, Bergavagen 3, 25466 Helsingborg, Sweden.
| | - J M Steiner
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, 4474 TAMU, College Station, TX 77843-4474, USA
| | - P Razdan
- Halsinge Small Animal Clinic, Ullsattersvagen 8, 824 34 Hudiksvall, Sweden
| | - E Spodsberg
- Evidensia Specialist Animal Hospital, Bergavagen 3, 25466 Helsingborg, Sweden
| | - G Olmedal
- Evidensia Specialist Animal Hospital, Bergavagen 3, 25466 Helsingborg, Sweden
| | - J S Suchodolski
- Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, 4474 TAMU, College Station, TX 77843-4474, USA
| | - T Spillmann
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, Agnes Sjobergin katu 2, 00014 Helsinki, Finland
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33
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Toresson L, Steiner JM, Olmedal G, Larsen M, Suchodolski JS, Spillmann T. Oral cobalamin supplementation in cats with hypocobalaminaemia: a retrospective study. J Feline Med Surg 2017; 19:1302-1306. [PMID: 28128683 PMCID: PMC11104177 DOI: 10.1177/1098612x16689406] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Objectives The objective of the study was to evaluate whether oral cobalamin supplementation can restore normocobal-aminaemia in cats with hypocobalaminaemia and clinical signs of gastrointestinal disease. Methods This was a retrospective study based on a computerised database search for client-owned cats treated at Evidensia Specialist Animal Hospital, Helsingborg, Sweden, during the period December 2013 to August 2016. Inclusion criteria were cats with clinical signs of chronic enteropathy, an initial serum cobalamin concentration ⩽250 pmol/l (reference interval 214-738 pmol/l) and oral treatment with cobalamin tablets. Results Twenty-five cats met the inclusion criteria. The cats were treated with 0.25 mg cyanocobalamin tablets once daily. Serum cobalamin concentration was rechecked 27-94 days after continuous oral cobalamin supplementation. All cats had serum cobalamin concentrations above the reference interval after oral cobalamin supplementation. Median (range) serum cobalamin concentration was 128 pmol/l (111-250 pmol/l) prior to treatment and 2701 pmol/l (738-16,359 pmol/l) after supplementation. This difference was statistically significant ( P <0.0001). Conclusions and relevance Our results suggest that oral cobalamin supplementation is effective in increasing serum cobalamin to supranormal concentrations in cats with hypocobalaminaemia. Thus, oral cobalamin supplementation is a promising alternative to parenteral administration. Prospective comparative studies in cats being treated with parenteral vs oral cobalamin supplementation in a larger number of patients are warranted before oral supplementation can be recommended for routine use.
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Affiliation(s)
- Linda Toresson
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, Helsinki, Finland
- Evidensia Specialist Animal Hospital, Helsingborg, Sweden
| | - Joerg M Steiner
- Gastrointestinal Laboratory, Texas A&M University, College Station, TX, USA
| | | | | | - Jan S Suchodolski
- Gastrointestinal Laboratory, Texas A&M University, College Station, TX, USA
| | - Thomas Spillmann
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, Helsinki, Finland
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Campanello GC, Lofgren M, Yokom AL, Southworth DR, Banerjee R. Switch I-dependent allosteric signaling in a G-protein chaperone-B 12 enzyme complex. J Biol Chem 2017; 292:17617-17625. [PMID: 28882898 DOI: 10.1074/jbc.m117.786095] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 08/14/2017] [Indexed: 11/06/2022] Open
Abstract
G-proteins regulate various processes ranging from DNA replication and protein synthesis to cytoskeletal dynamics and cofactor assimilation and serve as models for uncovering strategies deployed for allosteric signal transduction. MeaB is a multifunctional G-protein chaperone, which gates loading of the active 5'-deoxyadenosylcobalamin cofactor onto methylmalonyl-CoA mutase (MCM) and precludes loading of inactive cofactor forms. MeaB also safeguards MCM, which uses radical chemistry, against inactivation and rescues MCM inactivated during catalytic turnover by using the GTP-binding energy to offload inactive cofactor. The conserved switch I and II signaling motifs used by G-proteins are predicted to mediate allosteric regulation in response to nucleotide binding and hydrolysis in MeaB. Herein, we targeted conserved residues in the MeaB switch I motif to interrogate the function of this loop. Unexpectedly, the switch I mutations had only modest effects on GTP binding and on GTPase activity and did not perturb stability of the MCM-MeaB complex. However, these mutations disrupted multiple MeaB chaperone functions, including cofactor editing, loading, and offloading. Hence, although residues in the switch I motif are not essential for catalysis, they are important for allosteric regulation. Furthermore, single-particle EM analysis revealed, for the first time, the overall architecture of the MCM-MeaB complex, which exhibits a 2:1 stoichiometry. These EM studies also demonstrate that the complex exhibits considerable conformational flexibility. In conclusion, the switch I element does not significantly stabilize the MCM-MeaB complex or influence the affinity of MeaB for GTP but is required for transducing signals between MeaB and MCM.
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Affiliation(s)
- Gregory C Campanello
- From the Departments of Biological Chemistry, University of Michigan Medical Center, and
| | - Michael Lofgren
- From the Departments of Biological Chemistry, University of Michigan Medical Center, and
| | - Adam L Yokom
- From the Departments of Biological Chemistry, University of Michigan Medical Center, and.,the Department of Biological Chemistry and.,the Graduate Program in Chemical Biology, Life Sciences Institute, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| | - Daniel R Southworth
- From the Departments of Biological Chemistry, University of Michigan Medical Center, and.,the Department of Biological Chemistry and
| | - Ruma Banerjee
- From the Departments of Biological Chemistry, University of Michigan Medical Center, and
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An Amoebal Grazer of Cyanobacteria Requires Cobalamin Produced by Heterotrophic Bacteria. Appl Environ Microbiol 2017; 83:AEM.00035-17. [PMID: 28283521 DOI: 10.1128/aem.00035-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/03/2017] [Indexed: 01/22/2023] Open
Abstract
Amoebae are unicellular eukaryotes that consume microbial prey through phagocytosis, playing a role in shaping microbial food webs. Many amoebal species can be cultivated axenically in rich media or monoxenically with a single bacterial prey species. Here, we characterize heterolobosean amoeba LPG3, a recent natural isolate, which is unable to grow on unicellular cyanobacteria, its primary food source, in the absence of a heterotrophic bacterium, a Pseudomonas species coisolate. To investigate the molecular basis of this requirement for heterotrophic bacteria, we performed a screen using the defined nonredundant transposon library of Vibrio cholerae, which implicated genes in corrinoid uptake and biosynthesis. Furthermore, cobalamin synthase deletion mutations in V. cholerae and the Pseudomonas species coisolate do not support the growth of amoeba LPG3 on cyanobacteria. While cyanobacteria are robust producers of a corrinoid variant called pseudocobalamin, this variant does not support the growth of amoeba LPG3. Instead, we show that it requires cobalamin that is produced by the Pseudomonas species coisolate. The diversity of eukaryotes utilizing corrinoids is poorly understood, and this amoebal corrinoid auxotroph serves as a model for examining predator-prey interactions and micronutrient transfer in bacterivores underpinning microbial food webs.IMPORTANCE Cyanobacteria are important primary producers in aquatic environments, where they are grazed upon by a variety of phagotrophic protists and, hence, have an impact on nutrient flux at the base of microbial food webs. Here, we characterize amoebal isolate LPG3, which consumes cyanobacteria as its primary food source but also requires heterotrophic bacteria as a source of corrinoid vitamins. Amoeba LPG3 specifically requires the corrinoid variant produced by heterotrophic bacteria and cannot grow on cyanobacteria alone, as they produce a different corrinoid variant. This same corrinoid specificity is also exhibited by other eukaryotes, including humans and algae. This amoebal model system allows us to dissect predator-prey interactions to uncover factors that may shape microbial food webs while also providing insight into corrinoid specificity in eukaryotes.
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Li Z, Shanmuganathan A, Ruetz M, Yamada K, Lesniak NA, Kräutler B, Brunold TC, Koutmos M, Banerjee R. Coordination chemistry controls the thiol oxidase activity of the B 12-trafficking protein CblC. J Biol Chem 2017; 292:9733-9744. [PMID: 28442570 DOI: 10.1074/jbc.m117.788554] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 04/20/2017] [Indexed: 01/20/2023] Open
Abstract
The cobalamin or B12 cofactor supports sulfur and one-carbon metabolism and the catabolism of odd-chain fatty acids, branched-chain amino acids, and cholesterol. CblC is a B12-processing enzyme involved in an early cytoplasmic step in the cofactor-trafficking pathway. It catalyzes the glutathione (GSH)-dependent dealkylation of alkylcobalamins and the reductive decyanation of cyanocobalamin. CblC from Caenorhabditis elegans (ceCblC) also exhibits a robust thiol oxidase activity, converting reduced GSH to oxidized GSSG with concomitant scrubbing of ambient dissolved O2 The mechanism of thiol oxidation catalyzed by ceCblC is not known. In this study, we demonstrate that novel coordination chemistry accessible to ceCblC-bound cobalamin supports its thiol oxidase activity via a glutathionyl-cobalamin intermediate. Deglutathionylation of glutathionyl-cobalamin by a second molecule of GSH yields GSSG. The crystal structure of ceCblC provides insights into how architectural differences at the α- and β-faces of cobalamin promote the thiol oxidase activity of ceCblC but mute it in wild-type human CblC. The R161G and R161Q mutations in human CblC unmask its latent thiol oxidase activity and are correlated with increased cellular oxidative stress disease. In summary, we have uncovered key architectural features in the cobalamin-binding pocket that support unusual cob(II)alamin coordination chemistry and enable the thiol oxidase activity of ceCblC.
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Affiliation(s)
- Zhu Li
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| | - Aranganathan Shanmuganathan
- the Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
| | - Markus Ruetz
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| | - Kazuhiro Yamada
- the Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
| | - Nicholas A Lesniak
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| | - Bernhard Kräutler
- the Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria, and
| | - Thomas C Brunold
- the Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Markos Koutmos
- the Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
| | - Ruma Banerjee
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600,
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Kainrath S, Stadler M, Reichhart E, Distel M, Janovjak H. Green-Light-Induced Inactivation of Receptor Signaling Using Cobalamin-Binding Domains. Angew Chem Int Ed Engl 2017; 56:4608-4611. [PMID: 28319307 PMCID: PMC5396336 DOI: 10.1002/anie.201611998] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Indexed: 11/10/2022]
Abstract
Optogenetics and photopharmacology provide spatiotemporally precise control over protein interactions and protein function in cells and animals. Optogenetic methods that are sensitive to green light and can be used to break protein complexes are not broadly available but would enable multichromatic experiments with previously inaccessible biological targets. Herein, we repurposed cobalamin (vitamin B12) binding domains of bacterial CarH transcription factors for green-light-induced receptor dissociation. In cultured cells, we observed oligomerization-induced cell signaling for the fibroblast growth factor receptor 1 fused to cobalamin-binding domains in the dark that was rapidly eliminated upon illumination. In zebrafish embryos expressing fusion receptors, green light endowed control over aberrant fibroblast growth factor signaling during development. Green-light-induced domain dissociation and light-inactivated receptors will critically expand the optogenetic toolbox for control of biological processes.
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Affiliation(s)
- Stephanie Kainrath
- Synthetic Physiology, Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400, Klosterneuburg, Austria
| | - Manuela Stadler
- Innovative Cancer Models, Children's Cancer Research Institute (CCRI), Zimmermannplatz 10, 1090, Vienna, Austria
| | - Eva Reichhart
- Synthetic Physiology, Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400, Klosterneuburg, Austria
| | - Martin Distel
- Innovative Cancer Models, Children's Cancer Research Institute (CCRI), Zimmermannplatz 10, 1090, Vienna, Austria
| | - Harald Janovjak
- Synthetic Physiology, Institute of Science and Technology Austria (IST Austria), Am Campus 1, 3400, Klosterneuburg, Austria
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Kainrath S, Stadler M, Reichhart E, Distel M, Janovjak H. Grünlicht-induzierte Rezeptorinaktivierung durch Cobalamin-bindende Domänen. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201611998] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Stephanie Kainrath
- Synthetic Physiology; Institute of Science and Technology Austria (IST Austria); Am Campus 1 3400 Klosterneuburg Österreich
| | - Manuela Stadler
- Innovative Cancer Models; Children's Cancer Research Institute (CCRI); Zimmermannplatz 10 1090 Wien Österreich
| | - Eva Reichhart
- Synthetic Physiology; Institute of Science and Technology Austria (IST Austria); Am Campus 1 3400 Klosterneuburg Österreich
| | - Martin Distel
- Innovative Cancer Models; Children's Cancer Research Institute (CCRI); Zimmermannplatz 10 1090 Wien Österreich
| | - Harald Janovjak
- Synthetic Physiology; Institute of Science and Technology Austria (IST Austria); Am Campus 1 3400 Klosterneuburg Österreich
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Renal thrombotic microangiopathy in patients with cblC defect: review of an under-recognized entity. Pediatr Nephrol 2017; 32:733-741. [PMID: 27289364 PMCID: PMC5368212 DOI: 10.1007/s00467-016-3399-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 04/10/2016] [Accepted: 04/11/2016] [Indexed: 12/19/2022]
Abstract
Methylmalonic aciduria and homocystinuria, cobalamin C (cblC) type, is the most common genetic type of functional cobalamin (vitamin B12) deficiency. This metabolic disease is characterized by marked heterogeneity of neurocognitive disease (microcephaly, seizures, developmental delay, ataxia, hypotonia) and variable extracentral nervous system involvement (failure to thrive, cardiovascular, renal, ocular) manifesting predominantly early in life, sometimes during gestation. To enhance awareness and understanding of renal disease associated with cblC defect, we studied biochemical, genetic, clinical, and histopathological data from 36 patients. Consistent clinical chemistry features of renal disease were intravascular hemolysis, hematuria, and proteinuria in all patients, with nephrotic-range proteinuria observed in three. Renal function ranged from normal to renal failure, with eight patients requiring (intermittent) dialysis. Two thirds were diagnosed with atypical (diarrhea-negative) hemolytic uremic syndrome (HUS). Renal histopathology analyses of biopsy samples from 16 patients revealed glomerular lesions typical of thrombotic microangiopathy (TMA). Treatment with hydroxycobalamin improved renal function in the majority, including three in whom dialysis could be withdrawn. Neurological sequelae were observed in 44 % and cardiopulmonary involvement in 39 % of patients, with half of the latter group demonstrating pulmonary hypertension. Mortality reached 100 % in untreated patients and 79 and 56 % in those with cardiopulmonary or neurological involvement, respectively. In all patients presenting with unclear intravascular hemolysis, hematuria, and proteinuria, cblC defect should be ruled out by determination of blood/plasma homocysteine levels and/or genetic testing, irrespective of actual renal function and neurological status, to ensure timely diagnosis and treatment.
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Rizzo G, Laganà AS, Rapisarda AMC, La Ferrera GMG, Buscema M, Rossetti P, Nigro A, Muscia V, Valenti G, Sapia F, Sarpietro G, Zigarelli M, Vitale SG. Vitamin B12 among Vegetarians: Status, Assessment and Supplementation. Nutrients 2016; 8:E767. [PMID: 27916823 PMCID: PMC5188422 DOI: 10.3390/nu8120767] [Citation(s) in RCA: 177] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 11/23/2016] [Accepted: 11/23/2016] [Indexed: 02/06/2023] Open
Abstract
Cobalamin is an essential molecule for humans. It acts as a cofactor in one-carbon transfers through methylation and molecular rearrangement. These functions take place in fatty acid, amino acid and nucleic acid metabolic pathways. The deficiency of vitamin B12 is clinically manifested in the blood and nervous system where the cobalamin plays a key role in cell replication and in fatty acid metabolism. Hypovitaminosis arises from inadequate absorption, from genetic defects that alter transport through the body, or from inadequate intake as a result of diet. With the growing adoption of vegetarian eating styles in Western countries, there is growing focus on whether diets that exclude animal foods are adequate. Since food availability in these countries is not a problem, and therefore plant foods are sufficiently adequate, the most delicate issue remains the contribution of cobalamin, which is poorly represented in plants. In this review, we will discuss the status of vitamin B12 among vegetarians, the diagnostic markers for the detection of cobalamin deficiency and appropriate sources for sufficient intake, through the description of the features and functions of vitamin B12 and its absorption mechanism.
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Affiliation(s)
| | - Antonio Simone Laganà
- Unit of Gynecology and Obstetrics, Department of Human Pathology in Adulthood and Childhood, "G. Barresi", University of Messina, Via Consolare Valeria 1, Messina 98125, Italy.
| | - Agnese Maria Chiara Rapisarda
- Department of General Surgery and Medical Surgical Specialties, University of Catania, Via S. Sofia 78, Catania 95124, Italy.
| | - Gioacchina Maria Grazia La Ferrera
- Department of Gastroenterology and Digestive Endoscopy Maddalena Raimondi San Cataldo, Via Forlanini 5, San Cataldo, Caltanissetta 93017, Italy.
| | - Massimo Buscema
- Unit of Diabetology and Endocrino-Metabolic Diseases, Hospital for Emergency Cannizzaro, Via Messina 829, Catania 95126, Italy.
| | - Paola Rossetti
- Unit of Diabetology and Endocrino-Metabolic Diseases, Hospital for Emergency Cannizzaro, Via Messina 829, Catania 95126, Italy.
| | - Angela Nigro
- Unit of Diabetology and Endocrino-Metabolic Diseases, Hospital for Emergency Cannizzaro, Via Messina 829, Catania 95126, Italy.
| | - Vincenzo Muscia
- Unit of Diabetology and Endocrino-Metabolic Diseases, Hospital for Emergency Cannizzaro, Via Messina 829, Catania 95126, Italy.
| | - Gaetano Valenti
- Department of General Surgery and Medical Surgical Specialties, University of Catania, Via S. Sofia 78, Catania 95124, Italy.
| | - Fabrizio Sapia
- Department of General Surgery and Medical Surgical Specialties, University of Catania, Via S. Sofia 78, Catania 95124, Italy.
| | - Giuseppe Sarpietro
- Department of General Surgery and Medical Surgical Specialties, University of Catania, Via S. Sofia 78, Catania 95124, Italy.
| | - Micol Zigarelli
- Department of General Surgery and Medical Surgical Specialties, University of Catania, Via S. Sofia 78, Catania 95124, Italy.
| | - Salvatore Giovanni Vitale
- Unit of Gynecology and Obstetrics, Department of Human Pathology in Adulthood and Childhood, "G. Barresi", University of Messina, Via Consolare Valeria 1, Messina 98125, Italy.
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Zhao H, Ruberu K, Li H, Garner B. Cell Type-Specific Modulation of Cobalamin Uptake by Bovine Serum. PLoS One 2016; 11:e0167044. [PMID: 27893837 PMCID: PMC5125665 DOI: 10.1371/journal.pone.0167044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 11/07/2016] [Indexed: 12/04/2022] Open
Abstract
Tracking cellular 57Co-labelled cobalamin (57Co-Cbl) uptake is a well-established method for studying Cbl homeostasis. Previous studies established that bovine serum is not generally permissive for cellular Cbl uptake when used as a supplement in cell culture medium, whereas supplementation with human serum promotes cellular Cbl uptake. The underlying reasons for these differences are not fully defined. In the current study we address this question. We extend earlier observations by showing that fetal calf serum inhibits cellular 57Co-Cbl uptake by HT1080 cells (a fibrosarcoma-derived fibroblast cell line). Furthermore, we discovered that a simple heat-treatment protocol (95°C for 10 min) ameliorates this inhibitory activity for HT1080 cell 57Co-Cbl uptake. We provide evidence that the very high level of haptocorrin in bovine serum (as compared to human serum) is responsible for this inhibitory activity. We suggest that bovine haptocorrin competes with cell-derived transcobalamin for Cbl binding, and that cellular Cbl uptake may be minimised in the presence of large amounts of bovine haptocorrin that are present under routine in vitro cell culture conditions. In experiments conducted with AG01518 cells (a neonatal foreskin-derived fibroblast cell line), overall cellular 57Co-Cbl uptake was 86% lower than for HT1080 cells, cellular TC production was below levels detectable by western blotting, and heat treatment of fetal calf serum resulted in only a modest increase in cellular 57Co-Cbl uptake. We recommend a careful assessment of cell culture protocols should be conducted in order to determine the potential benefits that heat-treated bovine serum may provide for in vitro studies of mammalian cell lines.
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Affiliation(s)
- Hua Zhao
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
| | - Kalani Ruberu
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
| | - Hongyun Li
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
| | - Brett Garner
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- * E-mail:
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Ku CA, Ng JK, Karr DJ, Reznick L, Harding CO, Weleber RG, Pennesi ME. Spectrum of ocular manifestations in cobalamin C and cobalamin A types of methylmalonic acidemia. Ophthalmic Genet 2016; 37:404-414. [DOI: 10.3109/13816810.2015.1121500] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Cristy A. Ku
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Jacqueline K. Ng
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Daniel J. Karr
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Leah Reznick
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Cary O. Harding
- Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA
| | - Richard G. Weleber
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Mark E. Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
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Geesaman BM, Whitehouse WH, Viviano KR. Serum Cobalamin and Methylmalonic Acid Concentrations in Hyperthyroid Cats Before and After Radioiodine Treatment. J Vet Intern Med 2016; 30:560-5. [PMID: 26934857 PMCID: PMC4913605 DOI: 10.1111/jvim.13918] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/24/2015] [Accepted: 02/09/2016] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Hyperthyroidism, the most common endocrine disorder in cats, has been associated with low serum cobalamin concentrations. Whether this is a functional cobalamin deficiency of clinical importance has not been assessed. HYPOTHESIS/OBJECTIVES Cats with hyperthyroidism experience a functional cobalamin deficiency which correlates with their clinical catabolic state and is reversible with return of the euthyroid state. ANIMALS Thirty-nine client-owned hyperthyroid cats. METHODS Prospective observational study. Serum cobalamin, methylmalonic acid, and clinical scores were determined in each hyperthyroid cat at enrollment and when euthyroid (60 days after radioiodine treatment). RESULTS Five of the 39 hyperthyroid cats (13%) had a low serum cobalamin concentration ranging from <150 to 290 ng/L. Serum cobalamin concentrations normalized to >350 ng/L in 2 of the hypocobalaminemic cats once euthyroid. None of the hyperthyroid/hypocobalaminemic cats had increased serum methylmalonic acid concentrations (175-601 nmol/L). In cats with clinical and biochemical hyperthyroidism, there was no correlation between serum cobalamin concentrations with total T4 concentration (P = .12) or clinical scores including body weight (P = .11) and BCS (P = .54). CONCLUSIONS AND CLINICAL IMPORTANCE In this population of hyperthyroid cats, the prevalence of hypocobalaminemia was low. Specifically, hyperthyroid cats, in which concurrent gastrointestinal disease is unlikely. Hypocobalaminemia is not a functional deficiency requiring supplementation in hyperthyroid cats without gastrointestinal disease.
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Affiliation(s)
- B M Geesaman
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI
| | - W H Whitehouse
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI
| | - K R Viviano
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI
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Toresson L, Steiner JM, Suchodolski JS, Spillmann T. Oral Cobalamin Supplementation in Dogs with Chronic Enteropathies and Hypocobalaminemia. J Vet Intern Med 2015; 30:101-7. [PMID: 26648590 PMCID: PMC4913667 DOI: 10.1111/jvim.13797] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 09/12/2015] [Accepted: 10/22/2015] [Indexed: 01/06/2023] Open
Abstract
Background Cobalamin deficiency is commonly associated with chronic enteropathies (CE) in dogs and current treatment protocols recommend parenteral supplementation. In humans, several studies have reported equal efficacy of oral and parenteral cobalamin administration of cobalamin. Objectives To retrospectively evaluate whether oral cobalamin supplementation can restore normocobalaminemia in dogs with CE and hypocobalaminemia. Animals Fifty‐one client‐owned dogs with various signs of CE and hypocobalaminemia. Material and Methods Retrospective study based on a computerized database search for dogs treated at Evidensia Specialist Animal Hospital, Helsingborg, Sweden during January 2012–March 2014. Inclusion criteria were dogs with signs of CE, an initial serum cobalamin ≤270 ng/L (reference interval: 234–811 ng/L) and oral treatment with cobalamin tablets. Serum cobalamin for follow‐up was analyzed 20–202 days after continuous oral cobalamin supplementation started. Results All dogs became normocobalaminemic with oral cobalamin supplementation. The mean increase in serum cobalamin concentration after treatment was 794 ± 462 ng/L. Serum cobalamin concentrations were significantly higher after supplementation (mean 1017 ± 460 ng/L; P < .0001) than at baseline (mean 223 ± 33 ng/L). Conclusion and Clinical Importance Our results suggest that oral cobalamin supplementation is effective in normalizing serum cobalamin concentrations in dogs with CE. Prospective studies comparing cellular cobalamin status in dogs being treated with parenteral versus oral cobalamin supplementation are warranted before oral supplementation can be recommended for routine supplementation.
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Affiliation(s)
- L Toresson
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, Helsinki, Finland.,Evidensia Specialist Animal Hospital, Helsingborg, Sweden
| | - J M Steiner
- Gastrointestinal Laboratory, Texas A&M University, College Station, TX
| | - J S Suchodolski
- Gastrointestinal Laboratory, Texas A&M University, College Station, TX
| | - T Spillmann
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, Helsinki, Finland
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Yamada K, Gherasim C, Banerjee R, Koutmos M. Structure of Human B12 Trafficking Protein CblD Reveals Molecular Mimicry and Identifies a New Subfamily of Nitro-FMN Reductases. J Biol Chem 2015; 290:29155-66. [PMID: 26364851 PMCID: PMC4705922 DOI: 10.1074/jbc.m115.682435] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Indexed: 01/07/2023] Open
Abstract
In mammals, B12 (or cobalamin) is an essential cofactor required by methionine synthase and methylmalonyl-CoA mutase. A complex intracellular pathway supports the assimilation of cobalamin into its active cofactor forms and delivery to its target enzymes. MMADHC (the methylmalonic aciduria and homocystinuria type D protein), commonly referred to as CblD, is a key chaperone involved in intracellular cobalamin trafficking, and mutations in CblD cause methylmalonic aciduria and/or homocystinuria. Herein, we report the first crystal structure of the globular C-terminal domain of human CblD, which is sufficient for its interaction with MMADHC (the methylmalonic aciduria and homocystinuria type C protein), or CblC, and for supporting the cytoplasmic cobalamin trafficking pathway. CblD contains an α+β fold that is structurally reminiscent of the nitro-FMN reductase superfamily. Two of the closest structural relatives of CblD are CblC, a multifunctional enzyme important for cobalamin trafficking, and the activation domain of methionine synthase. CblD, CblC, and the activation domain of methionine synthase share several distinguishing features and, together with two recently described corrinoid-dependent reductive dehalogenases, constitute a new subclass within the nitro-FMN reductase superfamily. We demonstrate that CblD enhances oxidation of cob(II)alamin bound to CblC and that disease-causing mutations in CblD impair the kinetics of this reaction. The striking structural similarity of CblD to CblC, believed to be contiguous in the cobalamin trafficking pathway, suggests the co-option of molecular mimicry as a strategy for achieving its function.
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Affiliation(s)
- Kazuhiro Yamada
- From the Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814 and
| | - Carmen Gherasim
- the Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109-0600
| | - Ruma Banerjee
- the Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109-0600, To whom correspondence may be addressed. Tel.: 734-615-5238; E-mail:
| | - Markos Koutmos
- From the Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814 and , To whom correspondence may be addressed. Tel.: 301-295-9419; E-mail:
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47
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Abstract
B12 -antimetabolites are compounds that counteract the physiological effects of vitamin B12 and related natural cobalamins. Presented here is a structure- and reactivity-based concept of the specific 'antivitamins B12 ': it refers to analogues of vitamin B12 that display high structural similarity to the vitamin and are 'locked chemically' to prevent their metabolic conversion into the crucial organometallic B12 -cofactors. Application of antivitamins B12 to healthy laboratory animals is, thus, expected to induce symptoms of B12 -deficiency. Antivitamins B12 may, hence, be helpful in elucidating still largely puzzling pathophysiological phenomena associated with B12 -deficiency, and also in recognizing physiological roles of B12 that probably still remain to be discovered.
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Affiliation(s)
- Bernhard Kräutler
- Institute of Organic Chemistry & Center for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria).
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48
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Obeid R, Fedosov SN, Nexo E. Cobalamin coenzyme forms are not likely to be superior to cyano- and hydroxyl-cobalamin in prevention or treatment of cobalamin deficiency. Mol Nutr Food Res 2015; 59:1364-72. [PMID: 25820384 PMCID: PMC4692085 DOI: 10.1002/mnfr.201500019] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/25/2015] [Accepted: 03/25/2015] [Indexed: 12/12/2022]
Abstract
Methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl) are coenzymes for methionine synthase and methylmalonyl-CoA mutase, respectively. Hydroxylcobalamin (HOCbl) and cyanocobalamin (CNCbl) are frequently used for supplementation. MeCbl and AdoCbl have recently emerged as alternative forms in supplements. In the light of metabolic transformation of Cbl into its cofactor forms, this review discusses current evidence on efficacy and utility of different Cbl forms in preventing or treating Cbl deficiency. Cbl-transporting proteins bind and mediate the uptake of all aforementioned forms of Cbl. After internalization and lysosomal release, Cbl binds to the cytosolic chaperon MMACHC that is responsible for (i) flavin-dependent decyanation of [CN-Co3+]Cbl to [Co2+]Cbl; (ii) glutathione-dependent dealkylation of MeCbl and AdoCbl to [Co2+/1+]Cbl; and (iii) glutathione-dependent decyanation of CNCbl or reduction of HOCbl under anaerobic conditions. MMACHC shows a broad specificity for Cbl forms and supplies the Cbl2+ intermediate for synthesis of MeCbl and AdoCbl. Cobalamin chemistry, physiology, and biochemistry suggest that MeCbl and AdoCbl follow the same route of intracellular processing as CNCbl does. We conclude that supplementing MeCbl or AdoCbl is unlikely to be advantageous compared to CNCbl. On the other hand, there are obvious advantages of high parenteral doses (1–2 mg) of HOCbl in treating inborn errors of Cbl metabolism.
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Affiliation(s)
- Rima Obeid
- Aarhus Institute of Advanced Studies, , University of Aarhus, Aarhus, Denmark.,Department of Clinical Chemistry, University Hospital of the Saarland, Homburg, Germany
| | - Sergey N Fedosov
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus C, Denmark.,Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Ebba Nexo
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus C, Denmark
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49
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Abstract
Hydrogen sulfide (H₂S) has emerged as an important signaling molecule with beneficial effects on various cellular processes affecting, for example, cardiovascular and neurological functions. The physiological importance of H₂S is motivating efforts to develop strategies for modulating its levels. However, advancement in the field of H₂S-based therapeutics is hampered by fundamental gaps in our knowledge of how H₂S is regulated, its mechanism of action, and its molecular targets. This review provides an overview of sulfur metabolism; describes recent progress that has shed light on the mechanism of H₂S as a signaling molecule; and examines nutritional regulation of sulfur metabolism, which pertains to health and disease.
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Affiliation(s)
- Omer Kabil
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109-0600;
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50
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Deme JC, Hancock MA, Xia X, Shintre CA, Plesa M, Kim JC, Carpenter EP, Rosenblatt DS, Coulton JW. Purification and interaction analyses of two human lysosomal vitamin B12transporters: LMBD1 and ABCD4. Mol Membr Biol 2014; 31:250-61. [DOI: 10.3109/09687688.2014.990998] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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