1
|
Sension RJ, McClain TP, Michocki LB, Miller NA, Alonso-Mori R, Lima FA, Ardana-Lamas F, Biednov M, Chung T, Deb A, Jiang Y, Kaneshiro AK, Khakhulin D, Kubarych KJ, Lamb RM, Meadows JH, Otte F, Sofferman DL, Song S, Uemura Y, van Driel TB, Penner-Hahn JE. Structural Evolution of Photoexcited Methylcobalamin toward a CarH-like Metastable State: Evidence from Time-Resolved X-ray Absorption and X-ray Emission. J Phys Chem B 2024; 128:8131-8144. [PMID: 39150518 DOI: 10.1021/acs.jpcb.4c03729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
CarH is a protein photoreceptor that uses a form of B12, adenosylcobalamin (AdoCbl), to sense light via formation of a metastable excited state. Aside from AdoCbl bound to CarH, methylcobalamin (MeCbl) is the only other example─to date─of photoexcited cobalamins forming metastable excited states with lifetimes of nanoseconds or longer. The UV-visible spectra of the excited states of MeCbl and AdoCbl bound to CarH are similar. We have used transient Co K-edge X-ray absorption and X-ray emission spectroscopies in conjunction with transient absorption spectroscopy in the UV-visible region to characterize the excited states of MeCbl. These data show that the metastable excited state of MeCbl has a slightly expanded corrin ring and increased electron density on the cobalt, but only small changes in the axial bond lengths.
Collapse
Affiliation(s)
- 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
| | - Taylor P McClain
- Biophysics, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Lindsay B Michocki
- 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
| | - Roberto Alonso-Mori
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Frederico Alves Lima
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Fernando Ardana-Lamas
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Mykola Biednov
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Taewon Chung
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Aniruddha Deb
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Yifeng Jiang
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - April K Kaneshiro
- Department of Biological Chemistry, 1150 W. Medical Center Dr., Ann Arbor, Michigan 48109-0600, United States
| | - Dmitry Khakhulin
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Kevin J Kubarych
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Ryan M Lamb
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Joseph H Meadows
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| | - Florian Otte
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Danielle L Sofferman
- Program in Applied Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040, United States
| | - Sanghoon Song
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Yohei Uemura
- Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Tim B van Driel
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - James E Penner-Hahn
- Department of Chemistry, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
- Biophysics, University of Michigan, 930 N University Ave. Ann Arbor, Michigan 48109-1055, United States
| |
Collapse
|
2
|
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
|
3
|
Temova Rakuša Ž, Roškar R, Hickey N, Geremia S. Vitamin B 12 in Foods, Food Supplements, and Medicines-A Review of Its Role and Properties with a Focus on Its Stability. MOLECULES (BASEL, SWITZERLAND) 2022; 28:molecules28010240. [PMID: 36615431 PMCID: PMC9822362 DOI: 10.3390/molecules28010240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022]
Abstract
Vitamin B12, also known as the anti-pernicious anemia factor, is an essential micronutrient totally dependent on dietary sources that is commonly integrated with food supplements. Four vitamin B12 forms-cyanocobalamin, hydroxocobalamin, 5'-deoxyadenosylcobalamin, and methylcobalamin-are currently used for supplementation and, here, we provide an overview of their biochemical role, bioavailability, and efficacy in different dosage forms. Since the effective quantity of vitamin B12 depends on the stability of the different forms, we further provide a review of their main reactivity and stability under exposure to various environmental factors (e.g., temperature, pH, light) and the presence of some typical interacting compounds (oxidants, reductants, and other water-soluble vitamins). Further, we explore how the manufacturing process and storage affect B12 stability in foods, food supplements, and medicines and provide a summary of the data published to date on the content-related quality of vitamin B12 products on the market. We also provide an overview of the approaches toward their stabilization, including minimization of the destabilizing factors, addition of proper stabilizers, or application of some (innovative) technological processes that could be implemented and contribute to the production of high-quality vitamin B12 products.
Collapse
Affiliation(s)
| | - Robert Roškar
- Faculty of Pharmacy, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Neal Hickey
- Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
| | - Silvano Geremia
- Department of Chemical and Pharmaceutical Sciences, Centre of Excellence in Biocrystallography, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
- Correspondence:
| |
Collapse
|
4
|
Qadeer K, Arsalan A, Ahmad I, Fatima K, Anwar Z, Ahmed S, Khattak SUR, Mahmud S. Photochemical interaction of cyanocobalamin and hydroxocobalamin with cysteine. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2020.129441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
5
|
Weinstain R, Slanina T, Kand D, Klán P. Visible-to-NIR-Light Activated Release: From Small Molecules to Nanomaterials. Chem Rev 2020; 120:13135-13272. [PMID: 33125209 PMCID: PMC7833475 DOI: 10.1021/acs.chemrev.0c00663] [Citation(s) in RCA: 261] [Impact Index Per Article: 65.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Indexed: 02/08/2023]
Abstract
Photoactivatable (alternatively, photoremovable, photoreleasable, or photocleavable) protecting groups (PPGs), also known as caged or photocaged compounds, are used to enable non-invasive spatiotemporal photochemical control over the release of species of interest. Recent years have seen the development of PPGs activatable by biologically and chemically benign visible and near-infrared (NIR) light. These long-wavelength-absorbing moieties expand the applicability of this powerful method and its accessibility to non-specialist users. This review comprehensively covers organic and transition metal-containing photoactivatable compounds (complexes) that absorb in the visible- and NIR-range to release various leaving groups and gasotransmitters (carbon monoxide, nitric oxide, and hydrogen sulfide). The text also covers visible- and NIR-light-induced photosensitized release using molecular sensitizers, quantum dots, and upconversion and second-harmonic nanoparticles, as well as release via photodynamic (photooxygenation by singlet oxygen) and photothermal effects. Release from photoactivatable polymers, micelles, vesicles, and photoswitches, along with the related emerging field of photopharmacology, is discussed at the end of the review.
Collapse
Affiliation(s)
- Roy Weinstain
- School
of Plant Sciences and Food Security, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 6997801, Israel
| | - Tomáš Slanina
- Institute
of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 166 10 Prague, Czech Republic
| | - Dnyaneshwar Kand
- School
of Plant Sciences and Food Security, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 6997801, Israel
| | - Petr Klán
- Department
of Chemistry and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| |
Collapse
|
6
|
Toda MJ, Lodowski P, Thurman TM, Kozlowski PM. Light Mediated Properties of a Thiolato-Derivative of Vitamin B 12. Inorg Chem 2020; 59:17200-17212. [PMID: 33211475 DOI: 10.1021/acs.inorgchem.0c02414] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Vitamin B12 derivatives (Cbls = cobalamins) exhibit photolytic properties upon excitation with light. These properties can be modulated by several factors including the nature of the axial ligands. Upon excitation, homolytic cleavage of the organometallic bond to the upper axial ligand takes place in photolabile Cbls. The photosensitive nature of Cbls has made them potential candidates for light-activated drug delivery. The addition of a fluorophore to the nucleotide loop of thiolato Cbls has been shown to shift the region of photohomolysis to within the optical window of tissue (600-900 nm). With this possibility, there is a need to analyze photolytic properties of unique Cbls which contain a Co-S bond. Herein, the photodissociation of one such Cbl, namely, N-acetylcysteinylcobalamin (NACCbl), is analyzed based on density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. The S0 and S1 potential energy surfaces (PESs), as a function of axial bond lengths, were computed to determine the mechanism of photodissociation. Like other Cbls, the S1 PES contains metal-to-ligand charge transfer (MLCT) and ligand field (LF) regions, but there are some unique differences. Interestingly, the S1 PES of NACCbl contains three distinct minima regions opening several possibilities for the mechanism of radical pair (RP) formation. The mild photoresponsiveness, observed experimentally, can be attributed to the small gap in energy between the S1 and S0 PESs. Compared to other Cbls, the gap shown for NACCbl is neither exactly in line with the alkyl Cbls nor the nonalkyl Cbls.
Collapse
Affiliation(s)
- Megan J Toda
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States
| | - Piotr Lodowski
- Department of Theoretical Chemistry, Institute of Chemistry, University of Silesia in Katowice, Szkolna 9, PL-40 006 Katowice, Poland
| | - Todd M Thurman
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States
| | - Pawel M Kozlowski
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States
| |
Collapse
|
7
|
Boase NRB. Shining a Light on Bioorthogonal Photochemistry for Polymer Science. Macromol Rapid Commun 2020; 41:e2000305. [DOI: 10.1002/marc.202000305] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/29/2020] [Indexed: 01/05/2023]
Affiliation(s)
- Nathan R. B. Boase
- Centre for Materials Science Queensland University of Technology 2 George Street Brisbane QLD 4000 Australia
- School of Chemistry and Physics Queensland University of Technology 2 George Street Brisbane QLD 4000 Australia
| |
Collapse
|
8
|
Luciano MP, Nourian S, Gorka AP, Nani RR, Nagaya T, Kobayashi H, Schnermann MJ. A near-infrared light-mediated cleavable linker strategy using the heptamethine cyanine chromophore. Methods Enzymol 2020; 641:245-275. [PMID: 32713525 PMCID: PMC10763689 DOI: 10.1016/bs.mie.2020.04.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Optical methods offer the potential to manipulate living biological systems with exceptional spatial and temporal control. Caging bioactive molecules with photocleavable functional groups is an important strategy that could be applied to a range of problems, including the targeted delivery of otherwise toxic therapeutics. However existing approaches that require UV or blue light are difficult to apply in organismal settings due to issues of tissue penetration and light toxicity. Photocaging groups built on the heptamethine cyanine scaffold enable the targeted delivery of bioactive molecules using near-IR light (up to 780nm) in live animal settings. Here we provide a detailed procedure demonstrating the utility of the heptamethine cyanine caging group to create a light-cleavable linker between an antibody, panitumumab, and a therapeutic small molecule in the duocarmycin class of natural products. Descriptions of the design and synthesis of the small molecule component, assembly of the antibody conjugate, in vitro analysis of uncaging, in vivo imaging, and impact on tumor progression are provided.
Collapse
Affiliation(s)
- Michael P Luciano
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States
| | - Saghar Nourian
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States
| | - Alexander P Gorka
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States
| | - Roger R Nani
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States
| | - Tadanobu Nagaya
- Laboratory of Molecular Theranostics, NIH/NCI/CCR, Bethesda, MD, United States
| | - Hisataka Kobayashi
- Laboratory of Molecular Theranostics, NIH/NCI/CCR, Bethesda, MD, United States
| | - Martin J Schnermann
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, United States.
| |
Collapse
|
9
|
Reddy VS, Trinath J, Reddy GB. Implication of homocysteine in protein quality control processes. Biochimie 2019; 165:19-31. [PMID: 31269461 DOI: 10.1016/j.biochi.2019.06.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 06/26/2019] [Indexed: 12/22/2022]
Abstract
Homocysteine (Hcy) is a key metabolite generated during methionine metabolism. The elevated levels of Hcy in the blood are reffered to as hyperhomocystenimeia (HHcy). The HHcy is caused by impaired metabolism/deficiency of either folate or B12 or defects in Hcy metabolism. Accumulating evidence suggests that HHcy is associated with cardiovascular and brain diseases including atherosclerosis, endothelial injury, and stroke etc. Vitamin B12 (cobalamin; B12) is a water-soluble vitamin essential for two metabolic reactions. It acts as a co-factor for methionine synthase and L-methylmalonyl-CoA mutase. Besides, it is also vital for DNA synthesis and maturation of RBC. Deficiency of B12 is associated with haematological and neurological disorders. Hyperhomocysteinemia (HHcy)-induced toxicity is thought to be mediated by the accumulation of Hcy and its metabolites, homocysteinylated proteins. Cellular protein quality control (PQC) is essential for the maintenance of proteome integrity, and cell viability and its failure contributes to the development of multiple diseases. Chaperones, unfolded protein response (UPR), ubiquitin-proteasome system (UPS), and autophagy are analogous strategies of PQC that maintain cellular proteome integrity. Recently, multiple studies reported that HHcy responsible for perturbation of PQC by reducing chaperone levels, activating UPR, and impairing autophagy. Besides, HHcy also induce cytotoxicity, inflammation, protein aggregation and apoptosis. It has been shown that some of the factors including altered SIRT1-HSF1 axis and irreversible homocysteinylation of proteins are responsible for folate and/or B12 deficiency or HHcy-induced impairment of PQC. Therefore, this review highlights the current understanding of HHcy in the context of cellular PQC and their pathophysiological and clinical consequences, epigenomic changes, therapeutic implications of B12, and chemical chaperones based on cell culture and experimental animal models.
Collapse
Affiliation(s)
- V Sudhakar Reddy
- Biochemistry Division, National Institute of Nutrition, Hyderabad, India.
| | - Jamma Trinath
- Department of Biological Sciences, BITS-Pilani, 500078, Hyderabad Campus, Hyderabad, Telangana, India
| | | |
Collapse
|
10
|
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
| |
Collapse
|
11
|
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
| |
Collapse
|
12
|
Dereven’kov IA, Tsaba LV, Pokrovskaya EA, Makarov SV. Studies on the interaction of aquacobalamin with cysteinesulfinic and cysteic acids, hypotaurine and taurine. J COORD CHEM 2018. [DOI: 10.1080/00958972.2018.1515927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Ilia A. Dereven’kov
- Department of Food Chemistry, Ivanovo State University of Chemistry and Technology, Ivanovo, Russian Federation
| | - Lubov V. Tsaba
- Department of Food Chemistry, Ivanovo State University of Chemistry and Technology, Ivanovo, Russian Federation
| | - Elizaveta A. Pokrovskaya
- Department of Food Chemistry, Ivanovo State University of Chemistry and Technology, Ivanovo, Russian Federation
| | - Sergei V. Makarov
- Department of Food Chemistry, Ivanovo State University of Chemistry and Technology, Ivanovo, Russian Federation
| |
Collapse
|
13
|
McCue AC, Moreau WM, Shell TA. Visible Light-Induced Radical Mediated DNA Damage. Photochem Photobiol 2018; 94:545-551. [PMID: 29377197 DOI: 10.1111/php.12890] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 12/18/2017] [Indexed: 12/31/2022]
Abstract
Light-responsive compounds have been used to manipulate biological systems with spatial and temporal control of the event of interest. Illumination of alkylcobalamins with green light (>500 nm) produces carbon-centered radicals, which have been demonstrated to effectively cause DNA damage. Molecules that cause DNA and RNA strand scission are useful for studying polynucleotide structure and the binding of small molecules and proteins to polynucleotides. Most molecules that cause DNA damage in a light-dependent manner require high energy, short wavelength ultraviolet light, which is readily absorbed by nucleotide bases causing damage to the polynucleotides. Therefore, using alkylcobalamins is advantageous for causing strand scission of polynucleotides, because they are activated by light wavelengths that are not absorbed by nucleotide bases. Green-light illumination of methylcobalamin effectively causes DNA strand scission based on gel mobility assays. This cleavage is due to the generation of carbon-centered radicals based on the results of a radical trapping study. In addition, synthesis of an alkylcobalamin with a DNA binding moiety, spermine, improves DNA cleavage efficacy by an order of magnitude in comparison with methylcobalamin.
Collapse
Affiliation(s)
- Amelia C McCue
- Department of Chemistry, Saint Anselm College, Manchester, NH
| | | | - Thomas A Shell
- Department of Chemistry and Biochemistry, Norwich University, Northfield, VT
| |
Collapse
|
14
|
Rafiee S, Asadollahi K, Riazi G, Ahmadian S, Saboury AA. Vitamin B12 Inhibits Tau Fibrillization via Binding to Cysteine Residues of Tau. ACS Chem Neurosci 2017; 8:2676-2682. [PMID: 28841372 DOI: 10.1021/acschemneuro.7b00230] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Two mechanisms underlie the inhibitory/acceleratory action of chemical compounds on tau aggregation including the regulation of cellular kinases and phosphatases activity and direct binding to tau protein. Vitamin B12 is one of the tau polymerization inhibitors, and its deficiency is linked to inactivation of protein phosphatase 2A and subsequently hyperphosphorylation and aggregation of tau protein. Regarding the structure and function of vitamin B12 and tau protein, we assumed that vitamin B12 is also able to directly bind to tau protein. Hence, we investigated the interaction of vitamin B12 with tau protein in vitro using fluorometry and circular dichrosim. Interaction studies was followed by investigation into the effect of vitamin B12 on tau aggregation using ThT fluorescence, circular dichroism, transmission electron microscopy, and SDS-PAGE. The results indicated that vitamin B12 interacts with tau protein and prevents fibrillization of tau protein. Blocking the cysteine residues of tau confirmed the cysteine-mediated binding of vitamin B12 to tau and showed that binding to cysteine is essential for inhibitory effect of vitamin B12 on tau aggregation. SDS-PAGE analysis indicated that vitamin B12 inhibits tau aggregation and that tau oligomers formed in the presence of vitamin B12 are mostly SDS-soluble. We propose that direct binding of vitamin B12 is another mechanism underlying the inhibitory role of vitamin B12 on tau aggregation and neurodegeneration.
Collapse
Affiliation(s)
- Saharnaz Rafiee
- Institute of Biochemistry and Biophysics
(IBB), University of Tehran, Tehran, Iran
| | - Kazem Asadollahi
- Institute of Biochemistry and Biophysics
(IBB), University of Tehran, Tehran, Iran
| | - Gholamhossein Riazi
- Institute of Biochemistry and Biophysics
(IBB), University of Tehran, Tehran, Iran
| | - Shahin Ahmadian
- Institute of Biochemistry and Biophysics
(IBB), University of Tehran, Tehran, Iran
| | - Ali Akbar Saboury
- Institute of Biochemistry and Biophysics
(IBB), University of Tehran, Tehran, Iran
| |
Collapse
|