1
|
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. [PMID: 39012171 DOI: 10.1021/acs.biochem.4c00216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [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.
Collapse
|
2
|
Pérez-Castaño R, Aranda J, Widner FJ, Kieninger C, Deery E, Warren MJ, Orozco M, Elías-Arnanz M, Padmanabhan S, Kräutler B. The Rhodium Analogue of Coenzyme B 12 as an Anti-Photoregulatory Ligand Inhibiting Bacterial CarH Photoreceptors. Angew Chem Int Ed Engl 2024; 63:e202401626. [PMID: 38416546 DOI: 10.1002/anie.202401626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 02/23/2024] [Accepted: 02/23/2024] [Indexed: 02/29/2024]
Abstract
Coenzyme B12 (AdoCbl; 5'-deoxy-5'-adenosylcobalamin), the quintessential biological organometallic radical catalyst, has a formerly unanticipated, yet extensive, role in photoregulation in bacteria. The light-responsive cobalt-corrin AdoCbl performs this nonenzymatic role by facilitating the assembly of CarH photoreceptors into DNA-binding tetramers in the dark, suppressing gene expression. Conversely, exposure to light triggers the decomposition of this AdoCbl-bound complex by a still elusive photochemical mechanism, activating gene expression. Here, we have examined AdoRhbl, the non-natural rhodium analogue of AdoCbl, as a photostable isostructural surrogate for AdoCbl. We show that AdoRhbl closely emulates AdoCbl in its uptake by bacterial cells and structural functionality as a regulatory ligand for CarH tetramerization, DNA binding, and repressor activity. Remarkably, we find AdoRhbl is photostable even when bound "base-off/His-on" to CarH in vitro and in vivo. Thus, AdoRhbl, an antivitamin B12, also represents an unprecedented anti-photoregulatory ligand, opening a pathway to precisely target biomimetic inhibition of AdoCbl-based photoregulation, with new possibilities for selective antibacterial applications. Computational biomolecular analysis of AdoRhbl binding to CarH yields detailed structural insights into this complex, which suggest that the adenosyl group of photoexcited AdoCbl bound to CarH may specifically undergo a concerted non-radical syn-1,2-elimination mechanism, an aspect not previously considered for this photoreceptor.
Collapse
Affiliation(s)
- Ricardo Pérez-Castaño
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
| | - Juan Aranda
- Institute for Research in Biomedicine, IRB Barcelona), Baldiri Reixac 10-12, 08028, Barcelona, Spain
| | - Florian J Widner
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020, Innsbruck, Austria
| | - Christoph Kieninger
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020, Innsbruck, Austria
| | - Evelyne Deery
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK
| | - Martin J Warren
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK
- Quadram Institute Bioscience, Norwich Research Park, Norwich, NR4 7UQ, UK
| | - Modesto Orozco
- Institute for Research in Biomedicine, IRB Barcelona), Baldiri Reixac 10-12, 08028, Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona (Spain); the Joint BSC-IRB Research Program in Computational Biology, and Department of Biochemistry and Biomedicine, University of Barcelona, Baldiri Reixac 10-12, 08028, Barcelona, Spain
| | - Montserrat Elías-Arnanz
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, 30100, Murcia, Spain
| | - S Padmanabhan
- Instituto de Química Física Blas Cabrera (IQF-CSIC), Consejo Superior de Investigaciones Científicas (CSIC), 119 c/Serrano, 28006, Madrid, Spain
| | - Bernhard Kräutler
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020, Innsbruck, Austria
| |
Collapse
|
3
|
Fedosov SN, Nexo E, Heegaard CW. Kinetics of Cellular Cobalamin Uptake and Conversion: Comparison of Aquo/Hydroxocobalamin to Cyanocobalamin. Nutrients 2024; 16:378. [PMID: 38337663 PMCID: PMC10857013 DOI: 10.3390/nu16030378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/21/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
Cyanocobalamin (CNCbl) and aquo/hydroxocobalamin (HOCbl) are the forms of vitamin B12 that are most commonly used for supplementation. They are both converted to methylcobalamin (MeCbl) and 5'-deoxyadenosylcobalamin (AdoCbl), which metabolize homocysteine and methylmalonic acid, respectively. Here, we compare the kinetics of uptake and the intracellular transformations of radiolabeled CNCbl vs. HOCbl in HeLa cells. More HOCbl was accumulated over 4-48 h, but further extrapolation indicated similar uptake (>90%) for both vitamin forms. The initially synthesized coenzyme was MeCbl, which noticeably exceeded AdoCbl during 48 h. Yet, the synthesis of AdoCbl accelerated, and the predicted final levels of Cbls were MeCbl ≈ AdoCbl ≈ 40% and HOCbl ≈ 20%. The designed kinetic model revealed the same patterns of the uptake and turnover for CNCbl and HOCbl, apart from two steps. First, the "activating" intracellular processing of the internalized HOCbl was six-fold faster. Second, the detachment rates from the cell surface (when the "excessive" Cbl-molecules were refluxed into the external medium) related as 4:1 for CNCbl vs. HOCbl. This gave a two-fold faster cellular accumulation and processing of HOCbl vs. CNCbl. In medical terms, our data suggest (i) an earlier response to the treatment of Cbl-deficiency with HOCbl, and (ii) the manifestation of a successful treatment initially as a decrease in homocysteine.
Collapse
Affiliation(s)
- Sergey N. Fedosov
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark;
- Department of Clinical Medicine/Clinical Biochemistry, Aarhus University Hospital, 8200 Aarhus N, Denmark;
| | - Ebba Nexo
- Department of Clinical Medicine/Clinical Biochemistry, Aarhus University Hospital, 8200 Aarhus N, Denmark;
| | - Christian W. Heegaard
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark;
| |
Collapse
|
4
|
Mathew AR, Di Matteo G, La Rosa P, Barbati SA, Mannina L, Moreno S, Tata AM, Cavallucci V, Fidaleo M. Vitamin B12 Deficiency and the Nervous System: Beyond Metabolic Decompensation-Comparing Biological Models and Gaining New Insights into Molecular and Cellular Mechanisms. Int J Mol Sci 2024; 25:590. [PMID: 38203763 PMCID: PMC10778862 DOI: 10.3390/ijms25010590] [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: 11/27/2023] [Revised: 12/16/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
Vitamin B12 (VitB12) is a micronutrient and acts as a cofactor for fundamental biochemical reactions: the synthesis of succinyl-CoA from methylmalonyl-CoA and biotin, and the synthesis of methionine from folic acid and homocysteine. VitB12 deficiency can determine a wide range of diseases, including nervous system impairments. Although clinical evidence shows a direct role of VitB12 in neuronal homeostasis, the molecular mechanisms are yet to be characterized in depth. Earlier investigations focused on exploring the biochemical shifts resulting from a deficiency in the function of VitB12 as a coenzyme, while more recent studies propose a broader mechanism, encompassing changes at the molecular/cellular levels. Here, we explore existing study models employed to investigate the role of VitB12 in the nervous system, including the challenges inherent in replicating deficiency/supplementation in experimental settings. Moreover, we discuss the potential biochemical alterations and ensuing mechanisms that might be modified at the molecular/cellular level (such as epigenetic modifications or changes in lysosomal activity). We also address the role of VitB12 deficiency in initiating processes that contribute to nervous system deterioration, including ROS accumulation, inflammation, and demyelination. Consequently, a complex biological landscape emerges, requiring further investigative efforts to grasp the intricacies involved and identify potential therapeutic targets.
Collapse
Affiliation(s)
- Aimee Rachel Mathew
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (A.R.M.); (A.M.T.)
| | - Giacomo Di Matteo
- Department of Chemistry and Technology of Drugs, Sapienza University of Rome, 00185 Rome, Italy; (G.D.M.); (L.M.)
| | - Piergiorgio La Rosa
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy;
- European Center for Brain Research, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy
| | - Saviana Antonella Barbati
- Departmental Faculty of Medicine and Surgery, UniCamillus-Saint Camillus International University of Health Sciences, 00131 Rome, Italy;
| | - Luisa Mannina
- Department of Chemistry and Technology of Drugs, Sapienza University of Rome, 00185 Rome, Italy; (G.D.M.); (L.M.)
| | - Sandra Moreno
- Department of Science, University Roma Tre, 00146 Rome, Italy;
- Laboratory of Neurodevelopment, Neurogenetics and Neuromolecular Biology, IRCCS Fondazione Santa Lucia, 00179 Rome, Italy
| | - Ada Maria Tata
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (A.R.M.); (A.M.T.)
- Research Centre of Neurobiology “Daniel Bovet”, Sapienza University of Rome, 00185 Rome, Italy
| | - Virve Cavallucci
- Dipartimento di Medicina e Chirurgia Traslazionale, Università Cattolica del Sacro Cuore, 00168 Rome, Italy;
- Fondazione Policlinico Universitario “A. Gemelli” IRCCS, 00168 Rome, Italy
| | - Marco Fidaleo
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy; (A.R.M.); (A.M.T.)
- Research Center for Nanotechnology Applied to Engineering (CNIS), Sapienza University of Rome, 00185 Rome, Italy
| |
Collapse
|
5
|
Kojima Y, Mishiro-Sato E, Fujishita T, Satoh K, Kajino-Sakamoto R, Oze I, Nozawa K, Narita Y, Ogata T, Matsuo K, Muro K, Taketo MM, Soga T, Aoki M. Decreased liver B vitamin-related enzymes as a metabolic hallmark of cancer cachexia. Nat Commun 2023; 14:6246. [PMID: 37803016 PMCID: PMC10558488 DOI: 10.1038/s41467-023-41952-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 09/20/2023] [Indexed: 10/08/2023] Open
Abstract
Cancer cachexia is a complex metabolic disorder accounting for ~20% of cancer-related deaths, yet its metabolic landscape remains unexplored. Here, we report a decrease in B vitamin-related liver enzymes as a hallmark of systemic metabolic changes occurring in cancer cachexia. Metabolomics of multiple mouse models highlights cachexia-associated reductions of niacin, vitamin B6, and a glycine-related subset of one-carbon (C1) metabolites in the liver. Integration of proteomics and metabolomics reveals that liver enzymes related to niacin, vitamin B6, and glycine-related C1 enzymes dependent on B vitamins decrease linearly with their associated metabolites, likely reflecting stoichiometric cofactor-enzyme interactions. The decrease of B vitamin-related enzymes is also found to depend on protein abundance and cofactor subtype. These metabolic/proteomic changes and decreased protein malonylation, another cachexia feature identified by protein post-translational modification analysis, are reflected in blood samples from mouse models and gastric cancer patients with cachexia, underscoring the clinical relevance of our findings.
Collapse
Affiliation(s)
- Yasushi Kojima
- Division of Pathophysiology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan.
| | - Emi Mishiro-Sato
- Division of Pathophysiology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Teruaki Fujishita
- Division of Pathophysiology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Kiyotoshi Satoh
- Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata, 997-0052, Japan
| | - Rie Kajino-Sakamoto
- Division of Pathophysiology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Isao Oze
- Division of Cancer Epidemiology and Prevention, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Kazuki Nozawa
- Department of Clinical Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Yukiya Narita
- Department of Clinical Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Takatsugu Ogata
- Department of Clinical Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Keitaro Matsuo
- Division of Cancer Epidemiology and Prevention, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Kei Muro
- Department of Clinical Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Makoto Mark Taketo
- Colon Cancer Project, Kyoto University Hospital-iACT, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata, 997-0052, Japan
| | - Masahiro Aoki
- Division of Pathophysiology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan.
- Department of Cancer Physiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
| |
Collapse
|
6
|
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.
Collapse
Affiliation(s)
- Helder M Marques
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa.
| |
Collapse
|
7
|
Brenig C, Mestizo PD, Zelder F. Functionalisation of vitamin B 12 derivatives with a cobalt β-phenyl ligand boosters antimetabolite activity in bacteria. RSC Adv 2022; 12:28553-28559. [PMID: 36320527 PMCID: PMC9541496 DOI: 10.1039/d2ra05748d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 09/27/2022] [Indexed: 11/06/2022] Open
Abstract
This study describes the syntheses of four singly- and two doubly-modified vitamin B12 derivatives for generating antimetabolites of Lactobacillus delbrueckii (L. delbrueckii). The two most potent antagonists, a Coβ-phenyl-cobalamin-c,8-lactam and a 10-bromo-Coβ-phenylcobalamin combine a c-lactam or 10-bromo modification at the “eastern” site of the corrin ring with an artificial organometallic phenyl group instead of a cyano ligand at the β-site of the cobalt center. These two doubly-modified B12 antagonists (10 nM) inhibit fully B12-dependent (0.1 nM) growth of L. delbrueckii. In contrast to potent 10-bromo-Coβ-phenylcobalamin, single modified 10-bromo-Coβ-cyanocobalamin lacking the artificial organometallic phenyl ligand does not show any inhibitory effect. These results suggest, that the organometallic β-phenyl ligand at the Co center ultimately steers the metabolic effect of the 10-bromo-analogue. This study describes the syntheses of four singly- and two doubly-modified vitamin B12 derivatives for generating antimetabolites of Lactobacillus delbrueckii (L. delbrueckii).![]()
Collapse
Affiliation(s)
- Christopher Brenig
- Department of Chemistry, University of ZurichWinterthurerstrasse 190CH 8057 ZurichSwitzerlandhttps://www.felix-zelder.net+41 44 635 6803
| | - Paula Daniela Mestizo
- Department of Chemistry, University of ZurichWinterthurerstrasse 190CH 8057 ZurichSwitzerlandhttps://www.felix-zelder.net+41 44 635 6803
| | - Felix Zelder
- Department of Chemistry, University of ZurichWinterthurerstrasse 190CH 8057 ZurichSwitzerlandhttps://www.felix-zelder.net+41 44 635 6803
| |
Collapse
|
8
|
Affiliation(s)
- Bernhard Kräutler
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innsbruck, Austria.
| |
Collapse
|
9
|
Ruetz M, Koutmos M, Kräutler B. Antivitamins B 12: Synthesis and application as inhibitory ligand of the B 12-tailoring enzyme CblC. Methods Enzymol 2022; 668:157-178. [PMID: 35589193 DOI: 10.1016/bs.mie.2021.12.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Antivitamins B12 are non-natural corrinoids that have been designed to counteract the metabolic effects of vitamin B12 and related cobalamins (Cbls) in humans and other mammals. A basic structure- and reactivity-based concept typifies antivitamins B12 as close structural mimics of vitamin B12 that are not transformed by the cellular metabolism into organometallic B12-cofactors. Antivitamins B12 have the correct structure for efficient take-up and transport via the natural mammalian pathway for cobalamin assimilation. Thus they can be delivered to every cell in the body, where they are proposed to target and inhibit the Cbl tailoring enzyme CblC. Antivitamins B12 may be specifically inert Cbls or isostructural Cbl-analogues that carry a metal centre other than a cobalt-ion. The syntheses of two antivitamins B12 are detailed here, as are biochemical and crystallographic studies that provide insights into the crucial binding interactions of Cbl-based antivitamins B12 with the human B12-tailoring enzyme CblC. This key enzyme binds genuine antivitamins B12 as inert substrate mimics and enzyme inhibitors, effectively repressing the metabolic generation of the B12-cofactors. Hence, antivitamins B12 induce the diagnostic symptoms of (functional) B12-deficiency, as observed in healthy laboratory mice.
Collapse
Affiliation(s)
- Markus Ruetz
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Markos Koutmos
- Department of Chemistry, Program in Biophysics, Program in Chemical Biology, University of Michigan, Ann Arbor, MI, United States.
| | - Bernhard Kräutler
- Institute of Organic Chemistry and Center of Molecular Biosciences, University of Innsbruck, Innsbruck, Austria.
| |
Collapse
|
10
|
Brenig C, Mosberger L, Baumann K, Blacque O, Zelder F. Redox‐Neutral Syntheses and Electrochemical Studies of 10‐Bromo‐Substituted Light‐Stable Antivitamin B
12
Candidates. Helv Chim Acta 2021. [DOI: 10.1002/hlca.202100067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Christopher Brenig
- Department of Chemistry University of Zurich Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Leila Mosberger
- Department of Chemistry University of Zurich Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Katja Baumann
- Department of Chemistry University of Zurich Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Olivier Blacque
- Department of Chemistry University of Zurich Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Felix Zelder
- Department of Chemistry University of Zurich Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| |
Collapse
|
11
|
Tsybizova A, Brenig C, Kieninger C, Kräutler B, Chen P. Surprising Homolytic Gas Phase Co-C Bond Dissociation Energies of Organometallic Aryl-Cobinamides Reveal Notable Non-Bonded Intramolecular Interactions. Chemistry 2021; 27:7252-7264. [PMID: 33560580 PMCID: PMC8251903 DOI: 10.1002/chem.202004589] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Indexed: 01/12/2023]
Abstract
Aryl-cobalamins are a new class of organometallic structural mimics of vitamin B12 designed as potential 'antivitamins B12 '. Here, the first cationic aryl-cobinamides are described, which were synthesized using the newly developed diaryl-iodonium method. The aryl-cobinamides were obtained as pairs of organometallic coordination isomers, the stereo-structure of which was unambiguously assigned based on homo- and heteronuclear NMR spectra. The availability of isomers with axial attachment of the aryl group, either at the 'beta' or at the 'alpha' face of the cobalt-center allowed for an unprecedented comparison of the organometallic reactivity of such pairs. The homolytic gas-phase bond dissociation energies (BDEs) of the coordination-isomeric phenyl- and 4-ethylphenyl-cobinamides were determined by ESI-MS threshold CID experiments, furnishing (Co-Csp 2 )-BDEs of 38.4 and 40.6 kcal mol-1 , respectively, for the two β-isomers, and the larger BDEs of 46.6 and 43.8 kcal mol-1 for the corresponding α-isomers. Surprisingly, the observed (Co-Csp 2 )-BDEs of the Coβ -aryl-cobinamides were smaller than the (Co-Csp 3 )-BDE of Coβ -methyl-cobinamide. DFT studies and the magnitudes of the experimental (Co-Csp 2 )-BDEs revealed relevant contributions of non-bonded interactions in aryl-cobinamides, notably steric strain between the aryl and the cobalt-corrin moieties and non-bonded interactions with and among the peripheral sidechains.
Collapse
Affiliation(s)
- Alexandra Tsybizova
- Laboratorium für Organische ChemieDepartment of Chemistry and Applied BiosciencesETH ZürichZürichSwitzerland
| | - Christopher Brenig
- Institute of Organic Chemistry & Center of Molecular BiosciencesUniversity of InnsbruckInnsbruckAustria
| | - Christoph Kieninger
- Institute of Organic Chemistry & Center of Molecular BiosciencesUniversity of InnsbruckInnsbruckAustria
| | - Bernhard Kräutler
- Institute of Organic Chemistry & Center of Molecular BiosciencesUniversity of InnsbruckInnsbruckAustria
| | - Peter Chen
- Laboratorium für Organische ChemieDepartment of Chemistry and Applied BiosciencesETH ZürichZürichSwitzerland
| |
Collapse
|
12
|
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: 30] [Impact Index Per Article: 10.0] [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.
Collapse
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
| |
Collapse
|
13
|
Abstract
The recently delineated structure- and reactivity-based concept of antivitamins B12 has begun to bear fruit by the generation, and study, of a range of such B12 -dummies, either vitamin B12 -derived, or transition metal analogues that also represent potential antivitamins B12 or specific B12 -antimetabolites. As reviewed here, this has opened up new research avenues in organometallic B12 -chemistry and bioinorganic coordination chemistry. Exploratory studies with antivitamins B12 have, furthermore, revealed some of their potential, as pharmacologically interesting compounds, for inducing B12 -deficiency in a range of organisms, from hospital resistant bacteria to laboratory mice. The derived capacity of antivitamins B12 to induce functional B12 -deficiency in mammalian cells and organs also suggest their valuable potential as growth inhibitors of cancerous human and animal cells.
Collapse
Affiliation(s)
- Bernhard Kräutler
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI)University of Innsbruck6020InnsbruckAustria
| |
Collapse
|
14
|
Kieninger C, Wurst K, Podewitz M, Stanley M, Deery E, Lawrence AD, Liedl KR, Warren MJ, Kräutler B. Replacement of the Cobalt Center of Vitamin B
12
by Nickel: Nibalamin and Nibyric Acid Prepared from Metal‐Free B
12
Ligands Hydrogenobalamin and Hydrogenobyric Acid. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202008407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Christoph Kieninger
- Institute of Organic Chemistry University of Innsbruck 6020 Innsbruck Austria
- Center for Molecular Biosciences (CMBI) University of Innsbruck 6020 Innsbruck Austria
| | - Klaus Wurst
- Institute of General Inorganic and Theoretical Chemistry University of Innsbruck 6020 Innsbruck Austria
| | - Maren Podewitz
- Center for Molecular Biosciences (CMBI) University of Innsbruck 6020 Innsbruck Austria
- Institute of General Inorganic and Theoretical Chemistry University of Innsbruck 6020 Innsbruck Austria
| | - Maria Stanley
- School of Biosciences University of Kent Canterbury CT2 7NJ UK
| | - Evelyne Deery
- School of Biosciences University of Kent Canterbury CT2 7NJ UK
| | | | - Klaus R. Liedl
- Center for Molecular Biosciences (CMBI) University of Innsbruck 6020 Innsbruck Austria
- Institute of General Inorganic and Theoretical Chemistry University of Innsbruck 6020 Innsbruck Austria
| | - Martin J. Warren
- School of Biosciences University of Kent Canterbury CT2 7NJ UK
- Quadram Institute Bioscience Norwich Science Park Norwich NR4 7UQ UK
| | - Bernhard Kräutler
- Institute of Organic Chemistry University of Innsbruck 6020 Innsbruck Austria
- Center for Molecular Biosciences (CMBI) University of Innsbruck 6020 Innsbruck Austria
| |
Collapse
|
15
|
Kieninger C, Wurst K, Podewitz M, Stanley M, Deery E, Lawrence AD, Liedl KR, Warren MJ, Kräutler B. Replacement of the Cobalt Center of Vitamin B 12 by Nickel: Nibalamin and Nibyric Acid Prepared from Metal-Free B 12 Ligands Hydrogenobalamin and Hydrogenobyric Acid. Angew Chem Int Ed Engl 2020; 59:20129-20136. [PMID: 32686888 PMCID: PMC7693184 DOI: 10.1002/anie.202008407] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Indexed: 12/18/2022]
Abstract
The (formal) replacement of Co in cobalamin (Cbl) by NiII generates nibalamin (Nibl), a new transition-metal analogue of vitamin B12 . Described here is Nibl, synthesized by incorporation of a NiII ion into the metal-free B12 ligand hydrogenobalamin (Hbl), itself prepared from hydrogenobyric acid (Hby). The related NiII corrin nibyric acid (Niby) was similarly synthesized from Hby, the metal-free cobyric acid ligand. The solution structures of Hbl, and Niby and Nibl, were characterized by spectroscopic studies. Hbl features two inner protons bound at N2 and N4 of the corrin ligand, as discovered in Hby. X-ray analysis of Niby shows the structural adaptation of the corrin ligand to NiII ions and the coordination behavior of NiII . The diamagnetic Niby and Nibl, and corresponding isoelectronic CoI corrins, were deduced to be isostructural. Nibl is a structural mimic of four-coordinate base-off Cbls, as verified by its ability to act as a strong inhibitor of bacterial adenosyltransferase.
Collapse
Affiliation(s)
- Christoph Kieninger
- Institute of Organic ChemistryUniversity of Innsbruck6020InnsbruckAustria
- Center for Molecular Biosciences (CMBI)University of Innsbruck6020InnsbruckAustria
| | - Klaus Wurst
- Institute of GeneralInorganic and Theoretical ChemistryUniversity of Innsbruck6020InnsbruckAustria
| | - Maren Podewitz
- Center for Molecular Biosciences (CMBI)University of Innsbruck6020InnsbruckAustria
- Institute of GeneralInorganic and Theoretical ChemistryUniversity of Innsbruck6020InnsbruckAustria
| | - Maria Stanley
- School of BiosciencesUniversity of KentCanterburyCT2 7NJUK
| | - Evelyne Deery
- School of BiosciencesUniversity of KentCanterburyCT2 7NJUK
| | | | - Klaus R. Liedl
- Center for Molecular Biosciences (CMBI)University of Innsbruck6020InnsbruckAustria
- Institute of GeneralInorganic and Theoretical ChemistryUniversity of Innsbruck6020InnsbruckAustria
| | - Martin J. Warren
- School of BiosciencesUniversity of KentCanterburyCT2 7NJUK
- Quadram Institute BioscienceNorwich Science ParkNorwichNR4 7UQUK
| | - Bernhard Kräutler
- Institute of Organic ChemistryUniversity of Innsbruck6020InnsbruckAustria
- Center for Molecular Biosciences (CMBI)University of Innsbruck6020InnsbruckAustria
| |
Collapse
|
16
|
Salerno EV, Miller NA, Konar A, Salchner R, Kieninger C, Wurst K, Spears KG, Kräutler B, Sension RJ. Exceptional Photochemical Stability of the Co-C Bond of Alkynyl Cobalamins, Potential Antivitamins B 12 and Core Elements of B 12-Based Biological Vectors. Inorg Chem 2020; 59:6422-6431. [PMID: 32311266 PMCID: PMC7201400 DOI: 10.1021/acs.inorgchem.0c00453] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Alkynylcorrinoids
are a class of organometallic B12 derivatives,
recently rediscovered for use as antivitamins B12 and as
core components of B12-based biological vectors. They feature
exceptional photochemical and thermal stability of their characteristic
extra-short Co–C bond. We describe here the synthesis and structure
of 3-hydroxypropynylcobalamin (HOPryCbl) and photochemical experiments
with HOPryCbl, as well as of the related alkynylcobalamins: phenylethynylcobalamin
and difluoro-phenylethynylcobalamin. Ultrafast spectroscopic studies
of the excited state dynamics and mechanism for ground state recovery
demonstrate that the Co–C bond of alkynylcobalamins is stable,
with the Co–N bond and ring deformations mediating internal
conversion and ground state recovery within 100 ps. These studies
provide insights required for the rational design of photostable or
photolabile B12-based cellular vectors. Most alkylcobalamins are photolabile; in contrast, alkynylcobalamins
are photostable. Through time-resolved measurements, we demonstrate
for three alkynylcobalamins that the Co−C bond is stable (i.e.
“locked”), while expansion of the Co−N axial
bond (which is “unlocked”) and ring deformations mediate
internal conversion and ground state recovery within 100 ps. The barrier
for ground state recovery is independent of the R group on the alkynyl
ligand.
Collapse
Affiliation(s)
- Elvin V Salerno
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Nicholas A Miller
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Arkaprabha Konar
- Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040, United States
| | - Robert Salchner
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Christoph Kieninger
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Klaus Wurst
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Kenneth G Spears
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Bernhard Kräutler
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Roseanne J Sension
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States.,Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040, United States.,Biophysics, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| |
Collapse
|
17
|
Naik S, Mahalle N, Greibe E, Ostenfeld MS, Heegaard CW, Nexo E, Fedosov SN. Cyano-B12 or Whey Powder with Endogenous Hydroxo-B12 for Supplementation in B12 Deficient Lactovegetarians. Nutrients 2019; 11:nu11102382. [PMID: 31590426 PMCID: PMC6835307 DOI: 10.3390/nu11102382] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 12/31/2022] Open
Abstract
Lactovegetarians (n = 35) with low vitamin B12 (B12) status were intervened for eight weeks capsules containing cyano-B12 (CN-B12), (2 × 2.8 µg/day), or equivalent doses of endogenous B12 (mainly hydroxo-B12 (HO-B12)) in whey powder. Blood samples were examined at baseline, every second week during the intervention, and two weeks post-intervention. The groups did not differ at baseline in [global median (min/max)] plasma B12 [112(61/185)] pmol/L, holotranscobalamin [20(4/99)] pmol/L, folate [13(11/16)], the metabolites total homocysteine [18(9/52)] µmol/L and methylmalonic acid [0.90(0.28/2.5)] µmol/L, and the combined indicator of B12 status (4cB12) [-1.7(-3.0/-0.33)]. Both supplements caused significant effects, though none of the biomarkers returned to normal values. Total plasma B12 showed a higher increase in the capsule group compared to the whey powder group (p = 0.02). However, the increase of plasma holotranscobalamin (p = 0.06) and the lowering of the metabolites (p > 0.07) were alike in both groups. Thereby, the high total plasma B12 in the capsule group was not mirrored in enhanced B12 metabolism, possibly because the B12 surplus was mainly accumulated on an "inert" carrier haptocorrin, considered to be of marginal importance for tissue delivery of B12. In conclusion, we demonstrate that administration of whey powder (HO-B12) or capsules (CN-B12) equivalent to 5.6 µg of B12 daily for eight weeks similarly improves B12 status but does not normalize it. We document that the results for plasma B12 should be interpreted with caution following administration of CN-B12, since the change is disproportionately high compared to the responses of complementary biomarkers.
Collapse
Affiliation(s)
- Sadanand Naik
- Department of Pathology, Deenanath Mangeshkar Hospital and Research Center, Pune, 411004, India.
| | - Namita Mahalle
- Department of Pathology, Deenanath Mangeshkar Hospital and Research Center, Pune, 411004, India.
| | - Eva Greibe
- Department of Clinical Biochemistry and Institute of Clinical Medicine, Aarhus University Hospital, DK-8200 Aarhus N, Denmark.
| | | | - Christian W Heegaard
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus C, Denmark.
| | - Ebba Nexo
- Department of Clinical Biochemistry and Institute of Clinical Medicine, Aarhus University Hospital, DK-8200 Aarhus N, Denmark.
| | - Sergey N Fedosov
- Department of Molecular Biology and Genetics, Aarhus University, DK-8000 Aarhus C, Denmark.
| |
Collapse
|
18
|
Miller NA, Michocki LB, Alonso-Mori R, Britz A, Deb A, DePonte DP, Glownia JM, Kaneshiro AK, Kieninger C, Koralek J, Meadows JH, van Driel TB, Kräutler B, Kubarych KJ, Penner-Hahn JE, Sension RJ. Antivitamins B 12 in a Microdrop: The Excited-State Structure of a Precious Sample Using Transient Polarized X-ray Absorption Near-Edge Structure. J Phys Chem Lett 2019; 10:5484-5489. [PMID: 31483136 DOI: 10.1021/acs.jpclett.9b02202] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Polarized transient X-ray absorption near-edge structure (XANES) was used to probe the excited-state structure of a photostable B12 antivitamin (Coβ-2-(2,4-difluorophenyl)-ethynylcobalamin, F2PhEtyCbl). A drop-on-demand delivery system synchronized to the LCLS X-ray free electron laser pulses was implemented and used to measure the XANES difference spectrum 12 ps following excitation, exposing only ∼45 μL of sample. Unlike cyanocobalamin (CNCbl), where the Co-C bond expands 15-20%, the excited state of F2PhEtyCbl is characterized by little change in the Co-C bond, suggesting that the acetylide linkage raises the barrier for expansion of the Co-C bond. In contrast, the lower axial Co-NDMB bond is elongated in the excited state of F2PhEtyCbl by ca. 10% or more, comparable to the 10% elongation observed for Co-NDMB in CNCbl.
Collapse
Affiliation(s)
- Nicholas A Miller
- Department of Chemistry , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109-1055 , United States
| | - Lindsay B Michocki
- Department of Chemistry , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109-1055 , United States
| | - Roberto Alonso-Mori
- Linac Coherent Light Source , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - Alexander Britz
- Linac Coherent Light Source , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
- Stanford PULSE Institute , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - Aniruddha Deb
- Department of Chemistry , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109-1055 , United States
- Biophysics , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109-1055 , United States
| | - Daniel P DePonte
- Linac Coherent Light Source , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - James M Glownia
- Linac Coherent Light Source , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - April K Kaneshiro
- Department of Biological Chemistry , 1150 West Medical Center Drive , Ann Arbor , Michigan 48109-0600 , United States
| | - Christoph Kieninger
- Institute of Organic Chemistry & Center for Molecular Biosciences , University of Innsbruck , Innrain 80/82 , A-6020 Innsbruck , Austria
| | - Jake Koralek
- Linac Coherent Light Source , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - Joseph H Meadows
- Department of Chemistry , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109-1055 , United States
| | - Tim B van Driel
- Linac Coherent Light Source , SLAC National Accelerator Laboratory , 2575 Sand Hill Road , Menlo Park , California 94025 , United States
| | - Bernhard Kräutler
- Institute of Organic Chemistry & Center for Molecular Biosciences , University of Innsbruck , Innrain 80/82 , A-6020 Innsbruck , Austria
| | - Kevin J Kubarych
- Department of Chemistry , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109-1055 , United States
- Biophysics , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109-1055 , United States
| | - James E Penner-Hahn
- Department of Chemistry , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109-1055 , United States
- Biophysics , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109-1055 , United States
| | - Roseanne J Sension
- Department of Chemistry , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109-1055 , United States
- Biophysics , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109-1055 , United States
- Department of Physics , University of Michigan , 450 Church Street , Ann Arbor , Michigan 48109-1040 , United States
| |
Collapse
|
19
|
Bernard DJ, Pangilinan FJ, Cheng J, Molloy AM, Brody LC. Mice lacking the transcobalamin-vitamin B12 receptor, CD320, suffer from anemia and reproductive deficits when fed vitamin B12-deficient diet. Hum Mol Genet 2018; 27:3627-3640. [PMID: 30124850 PMCID: PMC6168973 DOI: 10.1093/hmg/ddy267] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 06/29/2018] [Accepted: 07/12/2018] [Indexed: 11/12/2022] Open
Abstract
In humans, poor nutrition, malabsorption and variation in cobalamin (vitamin B12) metabolic genes are associated with hematological, neurological and developmental pathologies. Cobalamin is transported from blood into tissues via the transcobalamin (TC) receptor encoded by the CD320 gene. We created mice carrying a targeted deletion of the mouse ortholog, Cd320. Knockout (KO) mice lacking this TC receptor have elevated levels of plasma methylmalonic acid and homocysteine but are otherwise healthy, viable, fertile and not anemic. To challenge the Cd320 KO mice we maintained them on a vitamin B12-deficient diet. After 5 weeks on this diet, reproductive failure develops in Cd320 KO females but not males. In vitro, homozygous Cd320 KO embryos from cobalamin-deficient Cd320 KO dams develop normally to embryonic day (E) 3.5, while in vivo, few uterine decidual implantation sites are observed at E7.5, suggesting that embryos perish around the time of implantation. Dietary restriction of vitamin B12 induces a severe macrocytic anemia in Cd320 KO mice after 10-12 months while control mice on this diet are anemia-free up to 2 years. Despite the severe anemia, cobalamin-deficient KO mice do not exhibit obvious neurological symptoms. Our results with Cd320 KO mice suggest that an alternative mechanism exists for mice to transport cobalamin independent of the Cd320 encoded receptor. Our findings with deficient diet are consistent with historical and epidemiological data suggesting that low vitamin B12 levels in humans are associated with infertility and developmental abnormalities. Our Cd320 KO mouse model is an ideal model system for studying vitamin B12 deficiency.
Collapse
Affiliation(s)
- David J Bernard
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Faith J Pangilinan
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jun Cheng
- Transgenic Mouse Core, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Anne M Molloy
- School of Medicine, Trinity College, Dublin, Ireland
| | - Lawrence C Brody
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
20
|
Abstract
Nine compounds are classified as water-soluble vitamins, eight B vitamins and one vitamin C. The vitamins are mandatory for the function of numerous enzymes and lack of one or more of the vitamins may lead to severe medical conditions. All the vitamins are supplied by food in microgram to milligram quantities and in addition some of the vitamins are synthesized by the intestinal microbiota. In the gastrointestinal tract, the vitamins are liberated from binding proteins and for some of the vitamins modified prior to absorption. Due to their solubility in water, they all require specific carriers to be absorbed. Our current knowledge concerning each of the vitamins differs in depth and focus and is influenced by the prevalence of conditions and diseases related to lack of the individual vitamin. Because of that we have chosen to cover slightly different aspects for the individual vitamins. For each of the vitamins, we summarize the physiological role, the steps involved in the absorption, and the factors influencing the absorption. In addition, for some of the vitamins, the molecular base for absorption is described in details, while for others new aspects of relevance for human deficiency are included. © 2018 American Physiological Society. Compr Physiol 8:1291-1311, 2018.
Collapse
Affiliation(s)
- Hamid M Said
- University of California-School of Medicine, Irvine, California, USA.,VA Medical Center, Long Beach, California, USA
| | - Ebba Nexo
- Department of Clinical Medicine, Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark
| |
Collapse
|
21
|
Lodowski P, Toda MJ, Ciura K, Jaworska M, Kozlowski PM. Photolytic Properties of Antivitamins B12. Inorg Chem 2018; 57:7838-7850. [DOI: 10.1021/acs.inorgchem.8b00956] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Piotr Lodowski
- Department of Theoretical Chemistry, Institute of Chemistry, University of Silesia in Katowice, Szkolna 9, PL-40 006 Katowice, Poland
| | - Megan J. Toda
- Department of Chemistry, University of Louisville, 2320 South Brook Street, Louisville, Kentucky 40292, United States
| | - Karolina Ciura
- Department of Theoretical Chemistry, Institute of Chemistry, University of Silesia in Katowice, Szkolna 9, PL-40 006 Katowice, Poland
| | - Maria Jaworska
- Department of Theoretical Chemistry, Institute of Chemistry, University of Silesia in Katowice, Szkolna 9, PL-40 006 Katowice, Poland
| | - Pawel M. Kozlowski
- Department of Chemistry, University of Louisville, 2320 South Brook Street, Louisville, Kentucky 40292, United States
- Department of Food Sciences, Medical University of Gdansk, Al. Gen. J. Hallera 107, 80-416 Gdansk, Poland
| |
Collapse
|
22
|
Kuda-Wedagedara AW, Workinger JL, Nexo E, Doyle RP, Viola-Villegas N. 89Zr-Cobalamin PET Tracer: Synthesis, Cellular Uptake, and Use for Tumor Imaging. ACS OMEGA 2017; 2:6314-6320. [PMID: 29104950 PMCID: PMC5664145 DOI: 10.1021/acsomega.7b01180] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 09/18/2017] [Indexed: 06/07/2023]
Abstract
Vitamin B12, or cobalamin (Cbl), is an essential nutrient. Acquisition, transport, and cellular internalization of Cbl are dependent on specific binding proteins and associated receptors. The circulating transport protein transcobalamin (TC) promotes cellular uptake via binding to specific receptors such as CD320, a receptor upregulated in several cancer cell lines. In this study, we report the successful synthesis of 89Zirconium-labeled Cbl that was derivatized with desferrioxamine (89Zr-Cbl). We document the purity of the tracer and its binding to TC compared with that of unmodified cyano-Cbl (CN-Cbl). In vitro studies employing the CD320 receptor-positive breast cancer cell line MDA-MB-453 showed a 6- to 10-fold greater uptake of 89Zr-Cbl when compared with the uptake in the presence of 200-fold excess of CN-Cbl at 37 °C. We used nude mice with MDA-MB-453 tumors to study the feasibility of employing the tracer to visualize CD320 positive tumors. In vivo positron emission tomography images displayed a clear visualization of the tumor with 1.42 ± 0.48 %ID/g uptake (n = 3) at 4 h after injection (p.i.) with the tracer retained at 48 h p.i. Ex vivo biodistribution studies using 89Zr-Cbl exhibited the highest uptake in kidney and liver at 48 h p.i. Results document the feasibility of synthesizing a Cbl-based tracer suitable for both in vivo and ex vivo studies of Cbl trafficking and with the potential to visualize tumors expressing TC receptors, such as CD320.
Collapse
Affiliation(s)
- Akhila
N. W. Kuda-Wedagedara
- Department
of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, Michigan 48202, United States
| | - Jayme L. Workinger
- Department
of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13102, United States
| | - Ebba Nexo
- Department
of Clinical Biochemistry and Institute of Clinical Medicine, Aarhus University Hospital, Aarhus 8000, Denmark
| | - Robert P. Doyle
- Department
of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13102, United States
- Department
of Medicine, State University of New York
Upstate Medical University, Syracuse, New York 13102, United States
| | - Nerissa Viola-Villegas
- Department
of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, Michigan 48202, United States
| |
Collapse
|
23
|
Structure of the human transcobalamin beta domain in four distinct states. PLoS One 2017; 12:e0184932. [PMID: 28910388 PMCID: PMC5599065 DOI: 10.1371/journal.pone.0184932] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/02/2017] [Indexed: 11/19/2022] Open
Abstract
Vitamin B12 (cyanocobalamin, CNCbl) is an essential cofactor-precursor for two biochemical reactions in humans. When ingested, cobalamins (Cbl) are transported via a multistep transport system into the bloodstream, where the soluble protein transcobalamin (TC) binds Cbl and the complex is taken up into the cells via receptor mediated endocytosis. Crystal structures of TC in complex with CNCbl have been solved previously. However, the initial steps of holo-TC assembly have remained elusive. Here, we present four crystal structures of the beta domain of human TC (TC-beta) in different substrate-bound states. These include the apo and CNCbl-bound states, providing insight into the early steps of holo-TC assembly. We found that in vitro assembly of TC-alpha and TC-beta to a complex was Cbl-dependent. We also determined the structure of TC-beta in complex with cobinamide (Cbi), an alternative substrate, shedding light on the specificity of TC. We finally determined the structure of TC-beta in complex with an inhibitory antivitamin B12 (anti-B12). We used this structure to model the binding of anti-B12 into full-length holo-TC and could rule out that the inhibitory function of anti-B12 was based on an inability to form a functional complex with TC.
Collapse
|
24
|
Brenig C, Ruetz M, Kieninger C, Wurst K, Kräutler B. Alpha- and Beta-Diastereoisomers of Phenylcobalamin from Cobalt-Arylation with Diphenyliodonium Chloride. Chemistry 2017; 23:9726-9731. [PMID: 28557054 DOI: 10.1002/chem.201701514] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Indexed: 11/07/2022]
Abstract
Organometallic aryl-cobalamins are B12 -derivatives featuring properties of potential 'B12 antivitamins'. Herein, we describe a new method for the preparation of aryl-cobalamins using versatile diaryliodonium salts as arylation agents. Formate or sodium borohydride reduction of aquocobalamin in presence of diphenyliodonium chloride furnished Coβ -phenyl-cobalamin PhCbl in a roughly 3:1 to 1:1 ratio with its coordination isomer αPhCbl, a first representative 'base-off' Coα -aryl-cobalamin. The new structures were secured by detailed spectroscopic analysis, supplemented by an X-ray crystal structure analysis of PhCbl. Both types of coordination isomers of the aryl-cobalamins promise to be useful molecular tools in biomedical and biological studies.
Collapse
Affiliation(s)
- Christopher Brenig
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Markus Ruetz
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Christoph Kieninger
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Klaus Wurst
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Bernhard Kräutler
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| |
Collapse
|
25
|
Ruetz M, Shanmuganathan A, Gherasim C, Karasik A, Salchner R, Kieninger C, Wurst K, Banerjee R, Koutmos M, Kräutler B. Inhibierung des humanen B12-verarbeitenden Enzyms CblC durch Antivitamine B12- Kristallstruktur des inaktiven ternären Komplexes mit dem Kosubstrat Glutathion. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201701583] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Markus Ruetz
- Institut für Organische Chemie und Zentrum für Molekulare, Biowissenschaften; Universität Innsbruck; 6020 Innsbruck Österreich
- University of Michigan Medical School; Ann Arbor MI 48109-0600 USA
| | | | - Carmen Gherasim
- University of Michigan Medical School; Ann Arbor MI 48109-0600 USA
- Department of Pathology; University of Utah School of Medicine; Salt Lake City UT USA
| | - Agnes Karasik
- Department of Biochemistry; Uniformed Services University of the Health Sciences; Bethesda MD 28104 USA
| | - Robert Salchner
- Institut für Organische Chemie und Zentrum für Molekulare, Biowissenschaften; Universität Innsbruck; 6020 Innsbruck Österreich
- Watercryst GmbH & Co; Kematen Österreich
| | - Christoph Kieninger
- Institut für Organische Chemie und Zentrum für Molekulare, Biowissenschaften; Universität Innsbruck; 6020 Innsbruck Österreich
| | - Klaus Wurst
- Institut für Allgemeine, Anorganische Chemie und Theoretische Chemie; Universität Innsbruck; Österreich
| | - Ruma Banerjee
- University of Michigan Medical School; Ann Arbor MI 48109-0600 USA
| | - Markos Koutmos
- Department of Biochemistry; Uniformed Services University of the Health Sciences; Bethesda MD 28104 USA
| | - Bernhard Kräutler
- Institut für Organische Chemie und Zentrum für Molekulare, Biowissenschaften; Universität Innsbruck; 6020 Innsbruck Österreich
| |
Collapse
|
26
|
Ruetz M, Shanmuganathan A, Gherasim C, Karasik A, Salchner R, Kieninger C, Wurst K, Banerjee R, Koutmos M, Kräutler B. Antivitamin B 12 Inhibition of the Human B 12 -Processing Enzyme CblC: Crystal Structure of an Inactive Ternary Complex with Glutathione as the Cosubstrate. Angew Chem Int Ed Engl 2017; 56:7387-7392. [PMID: 28544088 DOI: 10.1002/anie.201701583] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Indexed: 02/06/2023]
Abstract
B12 antivitamins are important and robust tools for investigating the biological roles of vitamin B12 . Here, the potential antivitamin B12 2,4-difluorophenylethynylcobalamin (F2PhEtyCbl) was prepared, and its 3D structure was studied in solution and in the crystal. Chemically inert F2PhEtyCbl resisted thermolysis of its Co-C bond at 100 °C, was stable in bright daylight, and also remained intact upon prolonged storage in aqueous solution at room temperature. It binds to the human B12 -processing enzyme CblC with high affinity (KD =130 nm) in the presence of the cosubstrate glutathione (GSH). F2PhEtyCbl withstood tailoring by CblC, and it also stabilized the ternary complex with GSH. The crystal structure of this inactivated assembly provides first insight into the binding interactions between an antivitamin B12 and CblC, as well as into the organization of GSH and a base-off cobalamin in the active site of this enzyme.
Collapse
Affiliation(s)
- Markus Ruetz
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, 6020, Innsbruck, Austria.,University of Michigan Medical School, Ann Arbor, USA
| | | | - Carmen Gherasim
- University of Michigan Medical School, Ann Arbor, USA.,Current address: Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Agnes Karasik
- Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Robert Salchner
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, 6020, Innsbruck, Austria.,Current address: Watercryst GmbH & Co, Kematen, Austria
| | - Christoph Kieninger
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, 6020, Innsbruck, Austria
| | - Klaus Wurst
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Austria
| | - Ruma Banerjee
- University of Michigan Medical School, Ann Arbor, USA
| | - Markos Koutmos
- Department of Biochemistry, Uniformed Services University of the Health Sciences, Bethesda, USA
| | - Bernhard Kräutler
- Institute of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, 6020, Innsbruck, Austria
| |
Collapse
|
27
|
Haegler P, Grünig D, Berger B, Terracciano L, Krähenbühl S, Bouitbir J. Hepatic Effects of Pharmacological Doses of Hydroxy-Cobalamin[c-lactam] in Mice. PLoS One 2017; 12:e0171026. [PMID: 28135329 PMCID: PMC5279765 DOI: 10.1371/journal.pone.0171026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 01/13/2017] [Indexed: 12/04/2022] Open
Abstract
The vitamin B12 analog hydroxy-cobalamin[c-lactam] (HCCL) impairs hepatic mitochondrial protein synthesis and function of the electron transport chain in rats. We aimed to establish an in vivo model for mitochondrial dysfunction in mice, which could be used to investigate hepatotoxicity of mitochondrial toxicants. In a first step, we performed a dose-finding study in mice treated with HCCL 0.4 mg/kg and 4 mg/kg i.p. for two to four weeks. The plasma methylmalonate concentration was strongly increased at 4 mg/kg starting at three weeks of treatment. We subsequently treated mice daily with 4 mg/kg HCCL i.p. for three weeks and characterized liver function and histology as well as liver mitochondrial function. We found an increase in liver weight in HCCL-treated mice, which was paralleled by hepatocellular accumulation of triglycerides. In liver homogenate of HCCL-treated mice, the complex I activity of the electron transport chain was reduced, most likely explaining hepatocellular triglyceride accumulation. The activity of CPT1 was not affected by methylmalonyl-CoA in isolated liver mitochondria. Despite impaired complex I activity, mitochondrial superoxide anion production was not increased and the hepatocellular glutathione (GSH) pool was maintained. Finally, the mitochondrial DNA content was not altered with HCCL treatment. In conclusion, treatment of mice with HCCL is associated with increased liver weight explained by hepatocellular triglyceride accumulation. Hepatocellular fat accumulation is most likely a consequence of impaired activity of the mitochondrial electron transport chain. The impairment of complex I activity is not strong enough to result in ROS accumulation and reduction of the GSH stores.
Collapse
Affiliation(s)
- Patrizia Haegler
- Division of Clinical Pharmacology & Toxicology, University Hospital, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - David Grünig
- Division of Clinical Pharmacology & Toxicology, University Hospital, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Benjamin Berger
- Division of Clinical Pharmacology & Toxicology, University Hospital, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Luigi Terracciano
- Swiss Center of Applied Human Toxicology, SCAHT, Basel, Switzerland
- Department of Molecular Pathology, Institute for Pathology, University Hospital, Basel, Switzerland
| | - Stephan Krähenbühl
- Division of Clinical Pharmacology & Toxicology, University Hospital, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
- Swiss Center of Applied Human Toxicology, SCAHT, Basel, Switzerland
- * E-mail:
| | - Jamal Bouitbir
- Division of Clinical Pharmacology & Toxicology, University Hospital, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
- Swiss Center of Applied Human Toxicology, SCAHT, Basel, Switzerland
| |
Collapse
|
28
|
Miller NA, Wiley TE, Spears KG, Ruetz M, Kieninger C, Kräutler B, Sension RJ. Toward the Design of Photoresponsive Conditional Antivitamins B12: A Transient Absorption Study of an Arylcobalamin and an Alkynylcobalamin. J Am Chem Soc 2016; 138:14250-14256. [DOI: 10.1021/jacs.6b05299] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Nicholas A. Miller
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Theodore E. Wiley
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Kenneth G. Spears
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Markus Ruetz
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Christoph Kieninger
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Bernhard Kräutler
- Institute of Organic Chemistry & Center for Molecular Biosciences, University of Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria
| | - Roseanne J. Sension
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| |
Collapse
|
29
|
Methylfolate Trap Promotes Bacterial Thymineless Death by Sulfa Drugs. PLoS Pathog 2016; 12:e1005949. [PMID: 27760199 PMCID: PMC5070874 DOI: 10.1371/journal.ppat.1005949] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 09/22/2016] [Indexed: 01/16/2023] Open
Abstract
The methylfolate trap, a metabolic blockage associated with anemia, neural tube defects, Alzheimer’s dementia, cardiovascular diseases, and cancer, was discovered in the 1960s, linking the metabolism of folate, vitamin B12, methionine and homocysteine. However, the existence or physiological significance of this phenomenon has been unknown in bacteria, which synthesize folate de novo. Here we identify the methylfolate trap as a novel determinant of the bacterial intrinsic death by sulfonamides, antibiotics that block de novo folate synthesis. Genetic mutagenesis, chemical complementation, and metabolomic profiling revealed trap-mediated metabolic imbalances, which induced thymineless death, a phenomenon in which rapidly growing cells succumb to thymine starvation. Restriction of B12 bioavailability, required for preventing trap formation, using an “antivitamin B12” molecule, sensitized intracellular bacteria to sulfonamides. Since boosting the bactericidal activity of sulfonamides through methylfolate trap induction can be achieved in Gram-negative bacteria and mycobacteria, it represents a novel strategy to render these pathogens more susceptible to existing sulfonamides. Sulfonamides were the first agents to successfully treat bacterial infections, but their use later declined due to the emergence of resistant organisms. Restoration of these drugs may be achieved through inactivation of molecular mechanisms responsible for resistance. A chemo-genomic screen first identified 50 chromosomal loci representing the whole-genome antifolate resistance determinants in Mycobacterium smegmatis. Interestingly, many determinants resembled components of the methylfolate trap, a metabolic blockage exclusively described in mammalian cells. Targeted mutagenesis, genetic and chemical complementation, followed by chemical analyses established the methylfolate trap as a novel mechanism of sulfonamide sensitivity, ubiquitously present in mycobacteria and Gram-negative bacterial pathogens. Furthermore, metabolomic analyses revealed trap-mediated interruptions in folate and related metabolic pathways. These metabolic imbalances induced thymineless death, which was reversible with exogenous thymine supplementation. Chemical restriction of vitamin B12, an important molecule required for prevention of the methylfolate trap, sensitized intracellular bacteria to sulfonamides. Thus, pharmaceutical promotion of the methylfolate trap represents a novel folate antagonistic strategy to render pathogenic bacteria more susceptible to available, clinically approved sulfonamides.
Collapse
|
30
|
Netsomboon K, Feßler A, Erletz L, Prüfert F, Ruetz M, Kieninger C, Kräutler B, Bernkop-Schnürch A. Vitamin B12 and derivatives—In vitro permeation studies across Caco-2 cell monolayers and freshly excised rat intestinal mucosa. Int J Pharm 2016; 497:129-35. [DOI: 10.1016/j.ijpharm.2015.11.043] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 11/24/2015] [Accepted: 11/25/2015] [Indexed: 11/25/2022]
|
31
|
Kornerup LS, Juul CB, Fedosov SN, Heegaard CW, Greibe E, Nexo E. Absorption and retention of free and milk protein-bound cyano- and hydroxocobalamins. An experimental study in rats. Biochimie 2015; 126:57-62. [PMID: 26626348 DOI: 10.1016/j.biochi.2015.11.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 11/23/2015] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Cobalamin/Vitamin B12 (Cbl) is an essential vitamin, supplied mainly as hydroxocobalamin (OHCbl) by animal products, including cows' milk. Cyanocobalamin (CNCbl) is the usual form in vitamin pills. The aim was to explore absorption and tissue accumulation of two Cbl forms, administered alone or bound to milk protein. MATERIALS AND METHODS We synthesized labeled OH[(57)Co]Cbl from commercially available CN[(57)Co]Cbl. Recombinant bovine transcobalamin (rbTC) was produced in yeast and skimmed milk obtained off the shelf. Male Wistar rats (250-300 g) received labeled Cbl by gastric gavage. First, we administered CN[(57)Co]Cbl, free or rbTC-bound (n = 15 in each group). Rats were sacrificed after two, 24, and 48 h. In the following studies, rats were sacrificed after 24 h. We compared absorption of free or rbTC-bound CN[(57)Co]Cbl added to cows' milk and analogous absorption of OH[(57)Co]Cbl, free or rbTC-bound, to absorption of free CN[(57)Co]Cbl, (n = 10 in each group). Blood, tissues, 24-h urine and feces were collected. Labeled Cbl was measured using a gamma counter. Results are expressed as percentage of administered dose. RESULTS Absorptions of CNCbl and OHCbl were neither influenced by rbTC-binding nor administration in milk. Absorption increased in the first 24 h with no further tissue accumulation during the subsequent 24 h. Accumulation of free CNCbl and (OHCbl) was 1.4, (4.1) (liver); 20.2, (16.4) (kidney); and 0.05, (0.02) (plasma)% 24 h after administration. Total organ accumulations were 21.6, (20.5)%. While total accumulations of CNCbl and OHCbl were equal, distributions between liver, kidney, and plasma showed significant differences (p < 0.0001; p = 0.01; p < 0.0001). CONCLUSIONS Cbl added to milk (spiked with rbTC) has high bioavailability matching that of free Cbl. OHCbl and CNCbl are absorbed equally well, but much more OHCbl accumulated in the liver. Benefits of oral supplementation with OHCbl compared to CNCbl should be investigated.
Collapse
Affiliation(s)
- L S Kornerup
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark.
| | - C B Juul
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - S N Fedosov
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark; Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - C W Heegaard
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - E Greibe
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark
| | - E Nexo
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark
| |
Collapse
|
32
|
Zelder F. Recent trends in the development of vitamin B12 derivatives for medicinal applications. Chem Commun (Camb) 2015; 51:14004-17. [PMID: 26287029 DOI: 10.1039/c5cc04843e] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This Feature Article highlights recent developments in the field of vitamin B12 derivatives for medicinal applications. The following topics are emphasized: (1) the development of aquacorrinoids for cyanide detection and detoxification, (2) the use of vitamin B12 conjugates and (3) antivitamins B12 for therapy and diagnosis, and (4) the design of corrinoids as activators of soluble guanylyl cyclase (sGC).
Collapse
Affiliation(s)
- Felix Zelder
- Department of Chemistry, University of Zürich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland.
| |
Collapse
|
33
|
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.
Collapse
Affiliation(s)
- Bernhard Kräutler
- Institute of Organic Chemistry & Center for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck (Austria).
| |
Collapse
|
34
|
Zelder F, Sonnay M, Prieto L. Antivitamins for Medicinal Applications. Chembiochem 2015; 16:1264-78. [PMID: 26013037 DOI: 10.1002/cbic.201500072] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Indexed: 12/14/2022]
Abstract
Antivitamins represent a broad class of compounds that counteract the essential effects of vitamins. The symptoms triggered by such antinutritional factors resemble those of vitamin deficiencies, but can be successfully reversed by treating patients with the intact vitamin. Despite being undesirable for healthy organisms, the toxicities of these compounds present considerable interest for biological and medicinal purposes. Indeed, antivitamins played fundamental roles in the development of pioneering antibiotic and antiproliferative drugs, such as prontosil and aminopterin. Their development and optimisation were made possible by the study, throughout the 20th century, of the vitamins' and antivitamins' functions in metabolic processes. However, even with this thorough knowledge, commercialised antivitamin-based drugs are still nowadays limited to antagonists of vitamins B9 and K. The antivitamin field thus still needs to be explored more intensely, in view of the outstanding therapeutic success exhibited by several antivitamin-based medicines. Here we summarise historical achievements and discuss critically recent developments, opportunities and potential limitations of the antivitamin approach, with a special focus on antivitamins K, B9 and B12 .
Collapse
Affiliation(s)
- Felix Zelder
- Institute of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich (Switzerland).
| | - Marjorie Sonnay
- Institute of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich (Switzerland)
| | - Lucas Prieto
- Institute of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich (Switzerland)
| |
Collapse
|
35
|
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.
Collapse
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
| |
Collapse
|
36
|
|