1
|
Chu JM, Baizhigitova D, Nguyen V, Zhang Y. Reusable HNO Sensors Derived from Cu Cyclam: A DFT Study on the Mechanistic Origin of High Reactivity and Favorable Conformation Changes and Potential Improvements. Inorg Chem 2024; 63:3586-3598. [PMID: 38307037 PMCID: PMC10880060 DOI: 10.1021/acs.inorgchem.3c04506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 01/17/2024] [Indexed: 02/04/2024]
Abstract
Nitroxyl (HNO) exhibits unique favorable properties in regulating biological and pharmacological activities. However, currently, there is only one Cu-based HNO sensor that can be recycled for reusable detection, which is a Cu cyclam derivative with a mixed thia/aza ligand. To elucidate the missing mechanistic origin of its high HNO reactivity and subsequent favorable conformation change toward a stable CuI product that is critical to be oxidized back by the physiological O2 level for HNO detection again, a density functional theory (DFT) computational study was performed. It not only reproduced experimental structural and reaction properties but also, more importantly, revealed an unknown role of the coordination atom in high reactivity. Its conformation change mechanism was found to not follow the previously proposed one but involve a novel favorable rotation pathway. Several newly designed complexes incorporating beneficial effects of coordination atoms and substituents to further enhance HNO reactivity while maintaining or even improving favorable conformation changes for reusable HNO detection were computationally validated. These novel results will facilitate the future development of reusable HNO sensors for true spatiotemporal resolution and repeated detection.
Collapse
Affiliation(s)
- Jia-Min Chu
- Department of Chemistry and
Chemical Biology, Stevens Institute of Technology, 1 Castle Point Terrace, Hoboken, New Jersey 07030, United States
| | - Dariya Baizhigitova
- Department of Chemistry and
Chemical Biology, Stevens Institute of Technology, 1 Castle Point Terrace, Hoboken, New Jersey 07030, United States
| | - Vy Nguyen
- Department of Chemistry and
Chemical Biology, Stevens Institute of Technology, 1 Castle Point Terrace, Hoboken, New Jersey 07030, United States
| | - Yong Zhang
- Department of Chemistry and
Chemical Biology, Stevens Institute of Technology, 1 Castle Point Terrace, Hoboken, New Jersey 07030, United States
| |
Collapse
|
2
|
Shi Y, Stella G, Chu J, Zhang Y. Mechanistic Origin of Favorable Substituent Effects in Excellent Cu Cyclam Based HNO Sensors. Angew Chem Int Ed Engl 2022; 61:e202211450. [PMID: 36048138 PMCID: PMC9633564 DOI: 10.1002/anie.202211450] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Indexed: 01/11/2023]
Abstract
HNO has broad chemical and biomedical properties. Metal complexes and derivatives are widely used to make excellent HNO sensors. However, their favorable mechanistic origins are largely unknown. Cu cyclam is a useful platform to make excellent HNO sensors including imaging agents. A quantum chemical study of Cu cyclams with various substitutions was performed, which reproduced diverse experimental reactivities. Structural, electronic, and energetic profiles along reaction pathways show the importance of HNO binding and a proton-coupled electron transfer mechanism for HNO reaction. Results reveal that steric effect is primary and electronic factor is secondary (if the redox potential is sufficient), but their interwoven effects can lead to unexpected reactivity, which looks mysterious experimentally but can be explained computationally. This work suggests rational substituent design ideas and recommends a theoretical study of a new design to save time and cost due to its subtle effect.
Collapse
Affiliation(s)
- Yelu Shi
- Department of Chemistry and Chemical BiologyStevens Institute of Technology1 Castle Point TerraceHobokenNJ 07030USA
| | - Gianna Stella
- Department of Chemistry and Chemical BiologyStevens Institute of Technology1 Castle Point TerraceHobokenNJ 07030USA
| | - Jia‐Min Chu
- Department of Chemistry and Chemical BiologyStevens Institute of Technology1 Castle Point TerraceHobokenNJ 07030USA
| | - Yong Zhang
- Department of Chemistry and Chemical BiologyStevens Institute of Technology1 Castle Point TerraceHobokenNJ 07030USA
| |
Collapse
|
3
|
Shi Y, Stella G, Chu JM, Zhang Y. Mechanistic Origin of Favorable Substituent Effects in Excellent Cu Cyclam Based HNO Sensors. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202211450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yelu Shi
- Stevens Institute of Technology Department of Chemistry and Chemical Biology UNITED STATES
| | - Gianna Stella
- Stevens Institute of Technology Department of Chemistry and Chemical Biology UNITED STATES
| | - Jia-Min Chu
- Stevens Institute of Technology Department of Chemistry and Chemical Biology UNITED STATES
| | - Yong Zhang
- Stevens Institute of Technology Department of Chemistry and Chemical Biology 1 Castle Point on Hudson 7030 Hoboken UNITED STATES
| |
Collapse
|
4
|
Shi Y, Michael MA, Zhang Y. HNO to NO Conversion Mechanism with Copper Zinc Superoxide Dismutase, Comparison with Heme Protein Mediated Conversions, and the Origin of Questionable Reversibility. Chemistry 2021; 27:5019-5027. [PMID: 33398888 DOI: 10.1002/chem.202100015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Indexed: 11/08/2022]
Abstract
The interconversion of NO and HNO, via copper zinc superoxide dismutase (CuZnSOD), is important in biomedicine and for HNO detection. Many mechanistic questions, including the decades-long debate on reversibility, were resolved in this work. Calculations of various active-site and full-protein models show that the basic mechanism is proton-coupled electron transfer with a computed barrier of 10.98 kcal mol-1 , which is in excellent agreement with experimental results (10.62 kcal mol-1 ), and this nonheme protein-mediated reaction has many significant mechanistic differences compared with the conversions mediated by heme proteins due to geometric and electronic factors. The reasons for the irreversible nature of this conversion and models with the first thermodynamically favorable and kinetically feasible mechanism for the experimental reverse reaction were discovered. Such results are the first for nonheme enzyme mediated HNO to NO conversions, which shall facilitate other related studies and HNO probe development.
Collapse
Affiliation(s)
- Yelu Shi
- Department of Chemistry and Chemical Biology, Stevens Institute, of Technology, 1 Castle Point on Hudson, Hoboken, NJ, 07030, USA.,College of Science and Technology, Wenzhou-Kean University, 88 Daxue Rd, Wenzhou, Zhejiang, 325060, P.R. China
| | - Matthew A Michael
- Department of Chemistry and Chemical Biology, Stevens Institute, of Technology, 1 Castle Point on Hudson, Hoboken, NJ, 07030, USA
| | - Yong Zhang
- Department of Chemistry and Chemical Biology, Stevens Institute, of Technology, 1 Castle Point on Hudson, Hoboken, NJ, 07030, USA
| |
Collapse
|
5
|
Updating NO •/HNO interconversion under physiological conditions: A biological implication overview. J Inorg Biochem 2020; 216:111333. [PMID: 33385637 DOI: 10.1016/j.jinorgbio.2020.111333] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/13/2020] [Accepted: 12/05/2020] [Indexed: 12/12/2022]
Abstract
Azanone (HNO/NO-), also called nitroxyl, is a highly reactive compound whose biological role is still a matter of debate. A key issue that remains to be clarified regarding HNO and its biological activity is that of its endogenous formation. Given the overlap of the molecular targets and reactivity of nitric oxide (NO•) and HNO, its chemical biology was perceived to be similar to that of NO• as a biological signaling agent. However, despite their closely related reactivity, NO• and HNO's biochemical pathways are quite different. Moreover, the reduction of nitric oxide to azanone is possible but necessarily coupled to other reactions, which drive the reaction forward, overcoming the unfavorable thermodynamic barrier. The mechanism of this NO•/HNO interplay and its downstream effects in different contexts were studied recently, showing that more than fifteen moderate reducing agents react with NO• producing HNO. Particularly, it is known that the reaction between nitric oxide and hydrogen sulfide (H2S) produces HNO. However, this rate constant was not reported yet. In this work, firstly the NO•/H2S effective rate constant was measured as a function of the pH. Then, the implications of these chemical (non-enzymatic), biologically compatible, routes to endogenous HNO formation was discussed. There is no doubt that HNO could be (is?) a new endogenously produced messenger that mediates specific physiological responses, many of which were attributed yet to direct NO• effects.
Collapse
|
6
|
Alday J, Mazzeo A, Suarez S. Selective detection of gasotransmitters using fluorescent probes based on transition metal complexes. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2020.119696] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
7
|
Orenha RP, Morgon NH, Contreras-García J, Silva GCG, Nagurniak GR, Piotrowski MJ, Caramori GF, Muñoz-Castro A, Parreira RLT. How does the acidic milieu interfere in the capability of ruthenium nitrosyl complexes to release nitric oxide? NEW J CHEM 2020. [DOI: 10.1039/c9nj04643g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The nitric oxide has a well-defined role in biology. The ruthenium complexes are model for study NO release mechanisms. The proton increases the capability of these compounds to release NO after reduction reaction or of the light supported reaction.
Collapse
Affiliation(s)
- Renato Pereira Orenha
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas
- Universidade de Franca
- Franca
- Brazil
| | | | | | | | | | | | - Giovanni Finoto Caramori
- Departamento de Química
- Universidade Federal de Santa Catarina
- Campus Universitário Trindade
- CP 476
- Florianópolis
| | - Alvaro Muñoz-Castro
- Laboratorio de Química Inorgánica y Materiales Moleculares
- Facultad de Ingenieria
- Universidad Autonoma de Chile
- San Miguel
- Chile
| | | |
Collapse
|
8
|
Maiti D, Islam ASM, Dutta A, Sasmal M, Prodhan C, Ali M. Dansyl-appended CuII-complex-based nitroxyl (HNO) sensing with living cell imaging application and DFT studies. Dalton Trans 2019; 48:2760-2771. [DOI: 10.1039/c8dt04564j] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We introduce herein, a novel copper complex-based fluorescent probe[CuII(DQ468)Cl]+that exhibits a significant fluorescence turn-on response towards nitroxyl with high selectivity over other biological reactive oxygen, nitrogen and sulfur species, including nitric oxide.
Collapse
Affiliation(s)
- Debjani Maiti
- Department of Chemistry Jadavpur University
- Kolkata 700 032
- India
| | | | - Ananya Dutta
- Department of Chemistry Jadavpur University
- Kolkata 700 032
- India
| | - Mihir Sasmal
- Department of Chemistry Jadavpur University
- Kolkata 700 032
- India
| | - Chandraday Prodhan
- Molecular & Human Genetics Division
- CSIR-Indian Institute of Chemical Biology
- Kolkata-700032
- India
| | - Mahammad Ali
- Department of Chemistry Jadavpur University
- Kolkata 700 032
- India
- Vice-Chancellor
- Aliah University
| |
Collapse
|
9
|
Shi Y, Zhang Y. Mechanisms of HNO Reactions with Ferric Heme Proteins. Angew Chem Int Ed Engl 2018; 57:16654-16658. [PMID: 30347123 PMCID: PMC6522253 DOI: 10.1002/anie.201807699] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Indexed: 02/06/2023]
Abstract
Many HNO-scavenging pathways exist to regulate its biological and pharmacological activities. Such reactions often involve ferric heme proteins and form an important basis for HNO probe development. However, mechanisms of HNO reactions with ferric heme proteins are largely unknown. We performed a computational investigation using metmyoglobin and catalase as representative ferric heme proteins with neutral and negatively charged axial ligands to provide the first detailed pathways. The results reproduced experimental barriers well with an average error of 0.11 kcal mol-1 . The rate-limiting step was found to be dissociation of the resting ligand or HNO coordination when there is no resting ligand. For both heme proteins, in contrast to the non-heme case, the reductive nitrosylation step was found to be barrierless proton-coupled electron transfer, which provides the major thermodynamic driving force for the overall reaction. The origin of the difference in reactivity between metmyoglobin and catalase was also revealed.
Collapse
Affiliation(s)
- Yelu Shi
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, 1 Castle Point on Hudson, Hoboken, NJ, 07030, USA
| | - Yong Zhang
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, 1 Castle Point on Hudson, Hoboken, NJ, 07030, USA
| |
Collapse
|
10
|
|
11
|
Smulik-Izydorczyk R, Dębowska K, Pięta J, Michalski R, Marcinek A, Sikora A. Fluorescent probes for the detection of nitroxyl (HNO). Free Radic Biol Med 2018; 128:69-83. [PMID: 29704623 DOI: 10.1016/j.freeradbiomed.2018.04.564] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 11/19/2022]
Abstract
Nitroxyl (HNO), which according to the IUPAC recommended nomenclature should be named azanone, is the protonated one-electron reduction product of nitric oxide. Recently, it has gained a considerable attention due to the interesting pharmacological effects of its donors. Although there has been great progress in the understanding of HNO chemistry and chemical biology, it still remains the most elusive reactive nitrogen species, and its selective detection is a real challenge. The development of reliable methodologies for the direct detection of azanone is essential for the understanding of important signaling properties of this reactive intermediate and its pharmacological potential. Over the last decade, there has been considerable progress in the development of low-molecular-weight fluorogenic probes for the detection of HNO, and therefore, in this review, we have focused on the challenges and limitations of and perspectives on nitroxyl detection based on the use of such probes.
Collapse
Affiliation(s)
- Renata Smulik-Izydorczyk
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Karolina Dębowska
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Jakub Pięta
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Radosław Michalski
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Andrzej Marcinek
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Adam Sikora
- Institute of Applied Radiation Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland.
| |
Collapse
|
12
|
Li H, Yao Q, Xu F, Xu N, Ma X, Fan J, Long S, Du J, Wang J, Peng X. Recognition of Exogenous and Endogenous Nitroxyl in Living Cells via a Two-Photon Fluorescent Probe. Anal Chem 2018. [DOI: 10.1021/acs.analchem.7b05172] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
13
|
Au-Yeung HY, Chan CY, Tong KY, Yu ZH. Copper-based reactions in analyte-responsive fluorescent probes for biological applications. J Inorg Biochem 2017; 177:300-312. [DOI: 10.1016/j.jinorgbio.2017.07.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/29/2017] [Accepted: 07/01/2017] [Indexed: 02/04/2023]
|
14
|
Ren M, Deng B, Zhou K, Wang JY, Kong X, Lin W. A targetable fluorescent probe for imaging exogenous and intracellularly formed nitroxyl in mitochondria in living cells. J Mater Chem B 2017; 5:1954-1961. [DOI: 10.1039/c6tb03388a] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have developed a new mitochondrial-targeted turn-on fluorescent HNO probe (Mito-HNO). Fluorescence imaging shows that Mito-HNO is suitable for ratiometric visualization of HNO within mitochondria in living cells.
Collapse
Affiliation(s)
- Mingguang Ren
- Institute of Fluorescent Probes for Biological Imaging
- School of Materials Science and Engineering
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
| | - Beibei Deng
- Institute of Fluorescent Probes for Biological Imaging
- School of Materials Science and Engineering
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
| | - Kai Zhou
- Institute of Fluorescent Probes for Biological Imaging
- School of Materials Science and Engineering
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
| | - Jian-Yong Wang
- Institute of Fluorescent Probes for Biological Imaging
- School of Materials Science and Engineering
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
| | - Xiuqi Kong
- Institute of Fluorescent Probes for Biological Imaging
- School of Materials Science and Engineering
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
| | - Weiying Lin
- Institute of Fluorescent Probes for Biological Imaging
- School of Materials Science and Engineering
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
| |
Collapse
|
15
|
Miao Z, King SB. Recent advances in the chemical biology of nitroxyl (HNO) detection and generation. Nitric Oxide 2016; 57:1-14. [PMID: 27108951 PMCID: PMC4910183 DOI: 10.1016/j.niox.2016.04.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 04/18/2016] [Indexed: 01/01/2023]
Abstract
Nitroxyl or azanone (HNO) represents the redox-related (one electron reduced and protonated) relative of the well-known biological signaling molecule nitric oxide (NO). Despite the close structural similarity to NO, defined biological roles and endogenous formation of HNO remain unclear due to the high reactivity of HNO with itself, soft nucleophiles and transition metals. While significant work has been accomplished in terms of the physiology, biology and chemistry of HNO, important and clarifying work regarding HNO detection and formation has occurred within the last 10 years. This review summarizes advances in the areas of HNO detection and donation and their application to normal and pathological biology. Such chemical biological tools allow a deeper understanding of biological HNO formation and the role that HNO plays in a variety of physiological systems.
Collapse
Affiliation(s)
- Zhengrui Miao
- Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109, USA
| | - S Bruce King
- Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109, USA.
| |
Collapse
|
16
|
Yang W, Chen X, Su H, Fang W, Zhang Y. The fluorescence regulation mechanism of the paramagnetic metal in a biological HNO sensor. Chem Commun (Camb) 2016; 51:9616-9. [PMID: 25947080 DOI: 10.1039/c5cc00787a] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Paramagnetic metals are frequently used to regulate fluorescence emissions in chemical and biological probes. Accurate quantum calculations offer the first regulation theory that quenching is through the competitive nonradiative decay of the mixed fluorophore/metal (3)ππ*/dd state isoenergetic to the fluorophore-localized (1)ππ* state.
Collapse
Affiliation(s)
- Wenjing Yang
- Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, Department of Chemistry, Beijing Normal University, Xin-wai-da-jie No. 19, Beijing, 100875, People's Republic of China.
| | | | | | | | | |
Collapse
|
17
|
Abucayon EG, Khade RL, Powell DR, Zhang Y, Richter-Addo GB. Hydride Attack on a Coordinated Ferric Nitrosyl: Experimental and DFT Evidence for the Formation of a Heme Model-HNO Derivative. J Am Chem Soc 2015; 138:104-7. [PMID: 26678216 DOI: 10.1021/jacs.5b12008] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Heme-HNO species are crucial intermediates in several biological processes. To date, no well-defined Fe heme-HNO model compounds have been reported. Hydride attack on the cationic ferric [(OEP)Fe(NO)(5-MeIm)]OTf (OEP = octaethylporphyrinato dianion) generates an Fe-HNO product that has been characterized by IR and (1)H NMR spectroscopy. Results of DFT calculations reveal a direct attack of the hydride on the N atom of the coordinated ferric nitrosyl.
Collapse
Affiliation(s)
- Erwin G Abucayon
- Department of Chemistry and Biochemistry, University of Oklahoma , Norman, Oklahoma 73019, United States
| | - Rahul L Khade
- Department of Biomedical Engineering, Chemistry and Biological Sciences, Stevens Institute of Technology , Castle Point on Hudson, Hoboken, New Jersey 07030, United States
| | - Douglas R Powell
- Department of Chemistry and Biochemistry, University of Oklahoma , Norman, Oklahoma 73019, United States
| | - Yong Zhang
- Department of Biomedical Engineering, Chemistry and Biological Sciences, Stevens Institute of Technology , Castle Point on Hudson, Hoboken, New Jersey 07030, United States
| | - George B Richter-Addo
- Department of Chemistry and Biochemistry, University of Oklahoma , Norman, Oklahoma 73019, United States
| |
Collapse
|
18
|
Rivera-Fuentes P, Lippard SJ. Metal-based optical probes for live cell imaging of nitroxyl (HNO). Acc Chem Res 2015; 48:2927-34. [PMID: 26550842 DOI: 10.1021/acs.accounts.5b00388] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nitroxyl (HNO) is a biological signaling agent that displays distinctive reactivity compared to nitric oxide (NO). As a consequence, these two reactive nitrogen species trigger different physiological responses. Selective detection of HNO over NO has been a challenge for chemists, and several fluorogenic molecular probes have been recently developed with that goal in mind. Common constructs take advantage of the HNO-induced reduction of Cu(II) to Cu(I). The sensing mechanism of such probes relies on the ability of the unpaired electron in a d orbital of the Cu(II) center to quench the fluorescence of a photoemissive ligand by either an electron or energy transfer mechanism. Experimental and theoretical mechanistic studies suggest that proton-coupled electron transfer mediates this process, and careful tuning of the copper coordination environment has led to sensors with optimized selectivity and kinetics. The current optical probes cover the visible and near-infrared regions of the spectrum. This palette of sensors comprises structurally and functionally diverse fluorophores such as coumarin (blue/green emission), boron dipyrromethane (BODIPY, green emission), benzoresorufin (red emission), and dihydroxanthenes (near-infrared emission). Many of these sensors have been successfully applied to detect HNO production in live cells. For example, copper-based optical probes have been used to detect HNO production in live mammalian cells that have been treated with H2S and various nitrosating agents. These studies have established a link between HSNO, the smallest S-nitrosothiol, and HNO. In addition, a near-infrared HNO sensor has been used to perform multicolor/multianalyte microscopy, revealing that exogenously applied HNO elevates the concentration of intracellular mobile zinc. This mobilization of zinc ions is presumably a consequence of nitrosation of cysteine residues in zinc-chelating proteins such as metallothionein. Future challenges for the optical imaging of HNO include devising probes that can detect HNO reversibly, especially because ratiometric imaging can only report equilibrium concentrations when the sensing event is reversible. Another important aspect that needs to be addressed is the creation of probes that can sense HNO in specific subcellular locations. These tools would be useful to identify the organelles in which HNO is produced in mammalian cells and probe the intracellular signaling networks in which this reactive nitrogen species is involved. In addition, near-infrared emitting probes might be applied to detect HNO in thicker specimens, such as acute tissue slices and even live animals, enabling the investigation of the roles of HNO in physiological or pathological conditions in multicellular systems.
Collapse
Affiliation(s)
- Pablo Rivera-Fuentes
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Stephen J. Lippard
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
19
|
Weisser F, Stevens H, Klein J, van der Meer M, Hohloch S, Sarkar B. Tailoring RuIIPyridine/Triazole Oxygenation Catalysts and Using Photoreactivity to Probe their Electronic Properties. Chemistry 2015; 21:8926-38. [DOI: 10.1002/chem.201406441] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Indexed: 12/17/2022]
|
20
|
Struppe J, Zhang Y, Rozovsky S. (77)Se chemical shift tensor of L-selenocystine: experimental NMR measurements and quantum chemical investigations of structural effects. J Phys Chem B 2015; 119:3643-50. [PMID: 25654666 DOI: 10.1021/jp510857s] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The genetically encoded amino acid selenocysteine and its dimeric form, selenocystine, are both utilized by nature. They are found in active sites of selenoproteins, enzymes that facilitate a diverse range of reactions, including the detoxification of reactive oxygen species and regulation of redox pathways. Due to selenocysteine and selenocystine's specialized biological roles, it is of interest to examine their (77)Se NMR properties and how those can in turn be employed to study biological systems. We report the solid-state (77)Se NMR measurements of the L-selenocystine chemical shift tensor, which provides the first experimental chemical shift tensor information on selenocysteine-containing systems. Quantum chemical calculations of L-selenocystine models were performed to help understand various structural effects on (77)Se L-selenocystine's chemical shift tensor. The effects of protonation state, protein environment, and substituent of selenium-bonded carbon on the isotropic chemical shift were found to be in a range of ca. 10-20 ppm. However, the conformational effect was found to be much larger, spanning ca. 600 ppm for the C-Se-Se-C dihedral angle range of -180° to +180°. Our calculations show that around the minimum energy structure with a C-Se-Se-C dihedral angle of ca. -90°, the energy costs to alter the dihedral angle in the range from -120° to -60° are within only 2.5 kcal/mol. This makes it possible to realize these conformations in a protein or crystal environment. (77)Se NMR was found to be a sensitive probe to such changes and has an isotropic chemical shift range of 272 ± 30 ppm for this energetically favorable conformation range. The energy-minimized structures exhibited calculated isotropic shifts that lay within 3-9% of those reported in previous solution NMR studies. The experimental solid-state NMR isotropic chemical shift is near the lower bound of this calculated range for these readily accessible conformations. These results suggest that the dihedral information may be deduced for a protein with appropriate structural models. These first-time experimental and theoretical results will facilitate future NMR studies of selenium-containing compounds and proteins.
Collapse
Affiliation(s)
- Jochem Struppe
- Bruker BioSpin Corporation, 15 Fortune Drive, Manning Park, Billerica, Massachusetts 01821, United States
| | | | | |
Collapse
|