1
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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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2
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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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3
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Fedosov SN, Nexo E, Heegaard CW. Low methylcobalamin in liver tissues is an artifact as shown by a revised extraction procedure. Biochim Biophys Acta Gen Subj 2023; 1867:130315. [PMID: 36739999 DOI: 10.1016/j.bbagen.2023.130315] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 01/10/2023] [Accepted: 01/23/2023] [Indexed: 02/05/2023]
Abstract
BACKGROUND Vitamin B12 (cobalamin, Cbl) is represented by several molecular variants distinguished by the exchangeable ligand X coordinated to cobalt ion (XCbl). The most typical XCbl-forms are cyanocobalamin (CNCbl), hydroxocobalamin (HOCbl), methylcobalamin (MeCbl) and 5'-deoxydeoxyadenosylcobalamin (AdoCbl). Cells convert the "inactive" vitamins CNCbl and HOCbl to the two critically important coenzymes AdoCbl or MeCbl. Surprisingly, little or no MeCbl is usually uncovered in the tissue samples, as compared to AdoCbl and HOCbl. We hypothesized that a low level of MeCbl is an artifact of "harsh" extractions, leading to degradation of MeCbl and/or its conversion to other XCbl-forms. METHODS We designed a "mild" extraction protocol, including homogenization of rat liver in ammonium acetate (pH 4.6), dilution with EtOH (final 60%) and heating for 10 min at 70 °C. The XCbls were separated by HPLC and quantified by isotope dilution assays. RESULTS A "mild" extraction revealed the following composition of Cbls: 37% AdoCbl, 35% MeCbl, 15% HOCbl and 13% CNCbl. The usual "harsh" protocol (pH 7, 20 min at 80 °C) changed this balance to 33%, 5%, 43% and 17%, respectively. A model assay revealed that MeCbl underwent demethylation and conversion to HOCbl at pH 3 and pH > 7, when heated with thiols. Other changes included decyanation of CNCbl and destruction of HOCbl. CONCLUSIONS Our procedure reveals a high content of MeCbl in rat liver. GENERAL SIGNIFICANCE This result challenges previous data and pinpoints the need for new studies to characterize the endogenous Cbl-forms in health and disease.
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Affiliation(s)
- Sergey N Fedosov
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, 8000 Aarhus C, Denmark; Department of Clinical Biochemistry, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark.
| | - Ebba Nexo
- Department of Clinical Biochemistry, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark.
| | - Christian W Heegaard
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, 8000 Aarhus C, Denmark.
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4
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Yu WL, Ren ZG, Ma KX, Yang HQ, Yang JJ, Zheng H, Wu W, Xu PF. Cobalt-catalyzed chemoselective dehydrogenation through radical translocation under visible light. Chem Sci 2022; 13:7947-7954. [PMID: 35865906 PMCID: PMC9258329 DOI: 10.1039/d2sc02291e] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 06/13/2022] [Indexed: 11/21/2022] Open
Abstract
The transformations that allow the direct removal of hydrogen from their corresponding saturated counterparts by the dehydrogenative strategy are a dream reaction that has remained largely underexplored. In this report, a straightforward and robust cobaloxime-catalyzed photochemical dehydrogenation strategy via intramolecular HAT is described for the first time. The reaction proceeds through an intramolecular radical translocation followed by the cobalt assisted dehydrogenation without needing any other external photosensitizers, noble-metals or oxidants. With this approach, a series of valuable unsaturated compounds such as α,β-unsaturated amides, enamides and allylic and homoallylic sulfonamides were obtained in moderate to excellent yields with good chemo- and regioselectivities, and the synthetic versatility was demonstrated by a range of transformations. And mechanistic studies of the method are discussed.
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Affiliation(s)
- Wan-Lei Yu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
- Frontiers Science Center for Rare Isotopes, Lanzhou University Lanzhou China
| | - Zi-Gang Ren
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
| | - Ke-Xing Ma
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
| | - Hui-Qing Yang
- Henan and Macquarie University Joint Centre for Biomedical Innovation, School of Life Sciences, Henan University Kaifeng 475004 China
| | - Jun-Jie Yang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
| | - Haixue Zheng
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou China
| | - Wangsuo Wu
- Frontiers Science Center for Rare Isotopes, Lanzhou University Lanzhou China
| | - Peng-Fei Xu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China
- State Key Laboratory of Veterinary Etiological Biology, College of Veterinary Medicine, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou China
- Frontiers Science Center for Rare Isotopes, Lanzhou University Lanzhou China
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5
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Mahwish N, Bairy LK, Srinivasamurthy S. Antivitamins: A Silver Lining in the Era of Antimicrobial Resistance. J Pharmacol Pharmacother 2022. [DOI: 10.1177/0976500x221080378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Antivitamins are compounds that negate the biological effects of vitamins. They have been successfully exploited for the development of various classes of drugs. In the early 19th century, the antifolate prontosil was developed for the treatment of puerperal fever. Since then, numerous other antifolates have been used to treat a wide range of infections. Antifolates, such as methotrexate, are potent anticancer agents and antivitamin K, such as warfarin, are used as anticoagulants. Despite several years of research, most antivitamin-based drugs are limited to vitamin K and B9, and the development of antagonists for other vitamins is still in the nascent stage. In the era of antimicrobial resistance, antivitamins can be considered as a promising alternative to develop newer antimicrobials and are worth exploring further. This review discusses key antivitamins at different stages of development which have potential utility as antibiotic drug candidates. The summary of studies of antivitamins in clinical development is also narrated.
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Affiliation(s)
- Nayesha Mahwish
- Department of Pharmacology, Ras Al Khaimah College of Medical Sciences (RAKCOMS), RAK Medical and Health Sciences University Ras Al Khaimah (RAKMHSU), Ras Al Khaimah, United Arab Emirates
| | - Laxminarayana Kurady Bairy
- Department of Pharmacology, Ras Al Khaimah College of Medical Sciences (RAKCOMS), RAK Medical and Health Sciences University Ras Al Khaimah (RAKMHSU), Ras Al Khaimah, United Arab Emirates
| | - Sureshkumar Srinivasamurthy
- Department of Pharmacology, Ras Al Khaimah College of Medical Sciences (RAKCOMS), RAK Medical and Health Sciences University Ras Al Khaimah (RAKMHSU), Ras Al Khaimah, United Arab Emirates
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6
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Affiliation(s)
- Bernhard Kräutler
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innsbruck, Austria.
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7
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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.
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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.
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8
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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.
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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
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9
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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: 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.
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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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10
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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.
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Affiliation(s)
- Bernhard Kräutler
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI)University of Innsbruck6020InnsbruckAustria
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11
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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
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12
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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.
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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
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13
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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.
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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
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14
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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.
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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
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15
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Demarteau J, Debuigne A, Detrembleur C. Organocobalt Complexes as Sources of Carbon-Centered Radicals for Organic and Polymer Chemistries. Chem Rev 2019; 119:6906-6955. [DOI: 10.1021/acs.chemrev.8b00715] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Jérémy Demarteau
- Center for Education and Research on Macromolecules (CERM), CESAM Research Unit, University of Liège, Allée du 6 Août, Building B6A, Agora Square, 4000 Liège, Belgium
| | - Antoine Debuigne
- Center for Education and Research on Macromolecules (CERM), CESAM Research Unit, University of Liège, Allée du 6 Août, Building B6A, Agora Square, 4000 Liège, Belgium
| | - Christophe Detrembleur
- Center for Education and Research on Macromolecules (CERM), CESAM Research Unit, University of Liège, Allée du 6 Août, Building B6A, Agora Square, 4000 Liège, Belgium
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16
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Toda MJ, Lodowski P, Mamun AA, Jaworska M, Kozlowski PM. Photolytic properties of the biologically active forms of vitamin B12. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2018.12.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Hassan S, Jackowska A, Gryko D. Truncated vitamin B12 derivative with the phosphate group retained. J PORPHYR PHTHALOCYA 2019. [DOI: 10.1142/s1088424619500421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cobyric acid and cobinamide are valuable building blocks for the synthesis of artificial cobalamins modified at the nucleotide loop. However, truncated vitamin B[Formula: see text] derivatives are devoid of the phosphate group. We have found that 2-iodoxy benzoic acid-mediated phosphorolysis leads to the cleavage of only one of the phosphodiester bond giving a vitamin B[Formula: see text] analogue with the phosphate moiety preserved. Subsequent alkylation with an organic halide establishes its role as a precursor for the synthesis of vitamin B[Formula: see text] mimics modified at the nucleotide loop.
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Affiliation(s)
- Sidra Hassan
- Institute of Organic Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Agnieszka Jackowska
- Institute of Organic Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Dorota Gryko
- Institute of Organic Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
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18
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Affiliation(s)
- Aleksandra J. Wierzba
- Institute of Organic ChemistryPolish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
| | - Sidra Hassan
- Institute of Organic ChemistryPolish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
| | - Dorota Gryko
- Institute of Organic ChemistryPolish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
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19
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Wierzba AJ, Maximova K, Wincenciuk A, Równicki M, Wojciechowska M, Nexø E, Trylska J, Gryko D. Does a Conjugation Site Affect Transport of Vitamin B 12 -Peptide Nucleic Acid Conjugates into Bacterial Cells? Chemistry 2018; 24:18772-18778. [PMID: 30286265 DOI: 10.1002/chem.201804304] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Indexed: 12/14/2022]
Abstract
Gram-negative bacteria develop specific systems for the uptake of scarce nutrients, including vitamin B12 . These uptake pathways may be utilized for the delivery of biologically relevant molecules into cells. Indeed, it was recently reported that vitamin B12 transported an antisense peptide nucleic acid (PNA) into Escherichia coli and Salmonella Typhimurium cells. The present studies indicate that the conjugation site of PNA to vitamin B12 has an impact on PNA transport into bacterial cells. Toward this end, a specifically designed PNA oligomer has been tethered at various positions of vitamin B12 (central Co, R5' -OH, c and e amide chains, meso position, and at the hydroxy group of cobinamide) by using known or newly developed methodologies and tested for the uptake of the synthesized conjugates by E. coli. Compounds in which the PNA oligonucleotide was anchored at the R5' -OH position were transported more efficiently than that of other compounds tethered at the peripheral positions around the corrin ring. Of importance is the fact that, contrary to mammalian organisms, E. coli also takes up cobinamide, which is an incomplete corrinoid. This selectivity opens up ways to fight bacterial infections.
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Affiliation(s)
- Aleksandra J Wierzba
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Ksenia Maximova
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Aleksandra Wincenciuk
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Marcin Równicki
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland.,College of Inter-Faculty Individual Studies in Mathematics, and Natural Sciences, Banacha 2c, 02-097, Warsaw, Poland
| | - Monika Wojciechowska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Ebba Nexø
- Department of Clinical Biochemistry, Aarhus University Hospital, PalleJuul-Jensens Boulevard 99, 8200, Aarhus N, Denmark
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Dorota Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
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20
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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
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21
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Jackowska A, Chromiński M, Giedyk M, Gryko D. 5′-Vitamin B12 derivatives suitable for bioconjugation via the amide bond. Org Biomol Chem 2018; 16:936-943. [DOI: 10.1039/c7ob02898a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Vitamin B12 derivatives bearing either the amino or the carboxylic group at the 5′-position were synthesised hence enabling conjugation of therapeutics to vitamin B12via the amide bond.
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Affiliation(s)
- A. Jackowska
- Institute of Organic Chemistry Polish Academy of Sciences
- 01-224 Warsaw
- Poland
| | - M. Chromiński
- Institute of Organic Chemistry Polish Academy of Sciences
- 01-224 Warsaw
- Poland
| | - M. Giedyk
- Institute of Organic Chemistry Polish Academy of Sciences
- 01-224 Warsaw
- Poland
| | - D. Gryko
- Institute of Organic Chemistry Polish Academy of Sciences
- 01-224 Warsaw
- Poland
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22
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Mutti E, Hunger M, Fedosov S, Nexo E, Kräutler B. Organometallic DNA-B 12 Conjugates as Potential Oligonucleotide Vectors: Synthesis and Structural and Binding Studies with Human Cobalamin-Transport Proteins. Chembiochem 2017; 18:2280-2291. [PMID: 28881087 DOI: 10.1002/cbic.201700472] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Indexed: 12/14/2022]
Abstract
The synthesis and structural characterization of Co-(dN)25 -Cbl (Cbl: cobalamin; dN: deoxynucleotide) and Co-(dN)39 -Cbl, which are organometallic DNA-B12 conjugates with single DNA strands consisting of 25 and 39 deoxynucleotides, respectively, and binding studies of these two DNA-Cbl conjugates to three homologous human Cbl transporting proteins, transcobalamin (TC), intrinsic factor (IF), and haptocorrin (HC), are reported. This investigation tests the suitability of such DNA-Cbls for the task of eventual in vivo oligonucleotide delivery. The binding of DNA-Cbl to TC, IF, and HC was investigated in competition with either a fluorescent Cbl derivative and Co-(dN)25 -Cbl, or radiolabeled vitamin B12 (57 Co-CNCbl) and Co-(dN)25 -Cbl or Co-(dN)39 -Cbl. Binding of the new DNA-Cbl conjugates was fast and tight with TC, but poorer with HC and IF, which extends a similar original finding with the simpler DNA-Cbl, Co-(dN)18 -Cbl. The contrasting affinities of TC versus IF and HC for the DNA-Cbl conjugates are rationalized herein by a stepwise mechanism of Cbl binding. Critical contributions to overall affinity result from gradual conformational adaptations of the Cbl-binding proteins to the DNA-Cbl, which is first bound to the respective β domains. This transition is fast with TC, but slow with IF and HC, with which weaker binding results. The invariably tight interaction of the DNA-Cbl conjugates with TC makes the Cbl moiety a potential natural vector for the specific delivery of oligonucleotide loads from the blood into cells.
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Affiliation(s)
- Elena Mutti
- Department of Clinical Biochemistry, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus N, Denmark
| | - Miriam Hunger
- Institute of Organic Chemistry, Center for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
| | - Sergey Fedosov
- Department of Molecular Biology and Genetics, Aarhus University, Science Park Gustav WiedsVej 10C, 8000, Aarhus C, Denmark
| | - Ebba Nexo
- Department of Clinical Biochemistry, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus N, Denmark
| | - Bernhard Kräutler
- Institute of Organic Chemistry, Center for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 80/82, 6020, Innsbruck, Austria
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23
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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.
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24
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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.
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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
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25
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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
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26
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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.
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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
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27
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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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28
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Lodowski P, Ciura K, Toda MJ, Jaworska M, Kozlowski PM. Photodissociation of ethylphenylcobalamin antivitamin B12. Phys Chem Chem Phys 2017; 19:30310-30315. [DOI: 10.1039/c7cp06589b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biologically active forms of cobalamins are crucial cofactors in biochemical reactions and these metabolites can be inhibited by their structurally similar analogues known as antivitamins B12.
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Affiliation(s)
- Piotr Lodowski
- Department of Theoretical Chemistry
- Institute of Chemistry
- University of Silesia in Katowice
- PL-40 006 Katowice
- Poland
| | - Karolina Ciura
- Department of Theoretical Chemistry
- Institute of Chemistry
- University of Silesia in Katowice
- PL-40 006 Katowice
- Poland
| | - Megan J. Toda
- Department of Chemistry
- University of Louisville
- Louisville
- USA
| | - Maria Jaworska
- Department of Theoretical Chemistry
- Institute of Chemistry
- University of Silesia in Katowice
- PL-40 006 Katowice
- Poland
| | - Pawel M. Kozlowski
- Department of Chemistry
- University of Louisville
- Louisville
- USA
- Department of Food Sciences
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29
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Abstract
This Perspective provides the first detailed overview of the photoresponse of vitamin B12 and its derivatives, from the early, photophysical events to the burgeoning area of B12-dependent photobiology.
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Affiliation(s)
- Alex R. Jones
- School of Chemistry
- Photon Science Institute and Manchester Institute of Biotechnology
- The University of Manchester
- Manchester
- UK
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30
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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
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31
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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: 28] [Impact Index Per Article: 3.5] [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.
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32
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Ó Proinsias K, Ociepa M, Pluta K, Chromiński M, Nexo E, Gryko D. Vitamin B12Phosphate Conjugation and Its Effect on Binding to the Human B12-Binding Proteins Intrinsic Factor and Haptocorrin. Chemistry 2016; 22:8282-9. [DOI: 10.1002/chem.201504898] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Indexed: 12/18/2022]
Affiliation(s)
- Keith Ó Proinsias
- Institute of Organic Chemistry PAS; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Michał Ociepa
- Institute of Organic Chemistry PAS; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Katarzyna Pluta
- Institute of Organic Chemistry PAS; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Mikołaj Chromiński
- Institute of Organic Chemistry PAS; Kasprzaka 44/52 01-224 Warsaw Poland
| | - Ebba Nexo
- Department of Clinical Biochemistry; Aarhus University Hospital; Norrebrogade 44 8000 Aarhus Denmark
| | - Dorota Gryko
- Institute of Organic Chemistry PAS; Kasprzaka 44/52 01-224 Warsaw Poland
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34
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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]
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35
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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).
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Affiliation(s)
- Felix Zelder
- Department of Chemistry, University of Zürich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland.
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36
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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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37
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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 .
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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)
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38
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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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39
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Gherasim C, Ruetz M, Li Z, Hudolin S, Banerjee R. Pathogenic mutations differentially affect the catalytic activities of the human B12-processing chaperone CblC and increase futile redox cycling. J Biol Chem 2015; 290:11393-402. [PMID: 25809485 DOI: 10.1074/jbc.m115.637132] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Indexed: 11/06/2022] Open
Abstract
Human CblC catalyzes the elimination of the upper axial ligand in cobalamin or B12 derivatives entering the cell from circulation. This processing step is critical for assimilation of dietary cobalamin into the active cofactor forms that support the B12-dependent enzymes, methionine synthase and methylmalonyl-CoA mutase. Using a modified nitroreductase scaffold tailored to bind cobalamin and glutathione, CblC exhibits versatility in the mechanism by which it removes cyano versus alkyl ligands in cobalamin. In this study, we have characterized the effects of two pathogenic missense mutations at the same residue, R161G and R161Q, which are associated with early and late onset of the CblC disorder, respectively. We find that the R161Q and R161G CblC mutants display lower protein stability and decreased dealkylation but not decyanation activity, suggesting that cyanocobalamin might be therapeutically useful for patients carrying mutations at Arg-161. The mutant proteins also exhibit impaired glutathione binding. In the presence of physiologically relevant glutathione concentrations, stabilization of the cob(II)alamin derivative is observed, which occurs at the expense of increased oxidation of glutathione. Futile redox cycling, which is suppressed in wild-type human CblC, explains the reported increase in oxidative stress levels associated with the CblC disorder.
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Affiliation(s)
- Carmen Gherasim
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| | - Markus Ruetz
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| | - Zhu Li
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| | - Stephanie Hudolin
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| | - Ruma Banerjee
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
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40
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Hunger M, Mutti E, Rieder A, Enders B, Nexo E, Kräutler B. Organometallic B12-DNA conjugate: synthesis, structure analysis, and studies of binding to human B12-transporter proteins. Chemistry 2014; 20:13103-7. [PMID: 25168390 DOI: 10.1002/chem.201404359] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Indexed: 11/12/2022]
Abstract
Design, synthesis, and structural characterization of a B12-octadecanucleotide are presented herein, a new organometallic B12-DNA conjugate. In such covalent conjugates, the natural B12 moiety may be a versatile vector for controlled in vivo delivery of oligonucleotides to cellular targets in humans and animals, through the endogenous B12 transport systems. Binding of the organometallic B12 octadecanucleotide to the three important human proteins of B12 transport was studied, to examine its structural suitability for the task of eventual in vivo oligonucleotide delivery. Binding was efficient with transcobalamin (TC), but not so efficient with the homologous glycoproteins intrinsic factor and haptocorrin. Binding of the B12 octadecanucleotide to TC suggests the capacity of the B12 moiety to serve as a natural vector for specific transport of single stranded, organometallic oligonucleotide loads from the blood stream into cells.
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Affiliation(s)
- Miriam Hunger
- Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI), Innrain 80/82, University of Innsbruck, 6020 Innsbruck (Austria)
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41
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Chromiński M, Lewalska A, Karczewski M, Gryko D. Vitamin B12 Derivatives for Orthogonal Functionalization. J Org Chem 2014; 79:7532-42. [DOI: 10.1021/jo501271g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Mikołaj Chromiński
- Institute
of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Agnieszka Lewalska
- Institute
of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Maksymilian Karczewski
- Institute
of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Dorota Gryko
- Institute
of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
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42
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Randaccio L, Brancatelli G, Demitri N, Dreos R, Hickey N, Siega P, Geremia S. Trans and Cis Effects of Axial Fluoroalkyl Ligands in Vitamin B12 Analogues: Relationship between Alkyl- and Fluoroalkyl-Cobalamins. Inorg Chem 2013; 52:13392-401. [DOI: 10.1021/ic401715e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Lucio Randaccio
- Department of Chemical
and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy
| | - Giovanna Brancatelli
- Department of Chemical
and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy
| | - Nicola Demitri
- Department of Chemical
and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy
| | - Renata Dreos
- Department of Chemical
and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy
| | - Neal Hickey
- Department of Chemical
and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy
| | - Patrizia Siega
- Department of Chemical
and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy
| | - Silvano Geremia
- Department of Chemical
and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy
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43
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Mutti E, Ruetz M, Birn H, Kräutler B, Nexo E. 4-ethylphenyl-cobalamin impairs tissue uptake of vitamin B12 and causes vitamin B12 deficiency in mice. PLoS One 2013; 8:e75312. [PMID: 24073261 PMCID: PMC3779197 DOI: 10.1371/journal.pone.0075312] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 08/13/2013] [Indexed: 11/18/2022] Open
Abstract
Coβ-4-ethylphenyl-cob(III) alamin (EtPhCbl) is an organometallic analogue of vitamin B12 (CNCbl) which binds to transcobalamin (TC), a plasma protein that facilitates the cellular uptake of cobalamin (Cbl). In vitro assays with key enzymes do not convert EtPhCbl to the active coenzyme forms of Cbl suggesting that administration of EtPhCbl may cause cellular Cbl deficiency. Here, we investigate the in vivo effect of EtPhCbl in mice and its ability, if any, to induce Cbl deficiency. We show that EtPhCbl binds to mouse TC and we examined mice that received 3.5 nmol/24h EtPhCbl (n=6), 3.5 nmol/24h CNCbl (n=7) or NaCl (control group) (n=5) through osmotic mini-pumps for four weeks. We analyzed plasma, urine, liver, spleen, submaxillary glands and spinal cord for Cbl and markers of Cbl deficiency including methylmalonic acid (MMA) and homocysteine (tHcy). Plasma MMA (mean±SEM) was elevated in animals treated with EtPhCbl (1.01±0.12 µmol/L) compared to controls (0.30±0.02 µmol/L) and CNCbl (0.29±0.01 µmol/L) treated animals. The same pattern was observed for tHcy. Plasma total Cbl concentration was higher in animals treated with EtPhCbl (128.82±1.87 nmol/L) than in CNCbl treated animals (87.64±0.93 nmol/L). However, the organ levels of total Cbl were significantly lower in animals treated with EtPhCbl compared to CNCbl treated animals or controls, notably in the liver (157.07±8.56 pmol/g vs. 603.85±20.02 pmol/g, and 443.09±12.32 pmol/g, respectively). Differences between the three groups was analysed using one-way ANOVA and, Bonferroni post-hoc test. EtPhCbl was present in all tissues, except the spinal cord, accounting for 35-90% of total Cbl. In conclusion, treatment with EtPhCbl induces biochemical evidence of Cbl deficiency. This may in part be caused by a compromised tissue accumulation of Cbl.
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Affiliation(s)
- Elena Mutti
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark
| | - Markus Ruetz
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
| | - Henrik Birn
- Department of Nephrology, Aarhus University Hospital and Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Bernhard Kräutler
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
| | - Ebba Nexo
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark
- * E-mail:
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44
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Ruetz M, Salchner R, Wurst K, Fedosov S, Kräutler B. Phenylethinylcobalamin: ein radikalsynthetisch hergestelltes, lichtstabiles und hitzeresistentes metallorganisches B12-Derivat. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201305206] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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45
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Ruetz M, Salchner R, Wurst K, Fedosov S, Kräutler B. Phenylethynylcobalamin: A Light-Stable and Thermolysis-Resistant Organometallic Vitamin B12Derivative Prepared by Radical Synthesis. Angew Chem Int Ed Engl 2013; 52:11406-9. [DOI: 10.1002/anie.201305206] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Indexed: 11/10/2022]
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46
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Chromiński M, Lewalska A, Gryko D. Reduction-free synthesis of stable acetylide cobalamins. Chem Commun (Camb) 2013; 49:11406-8. [DOI: 10.1039/c3cc47210h] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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47
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