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Karbalaei S, Franke A, Oppelt J, Aziz T, Jordan A, Pokkuluri PR, Schwartz DD, Ivanović-Burmazović I, Goldsmith CR. A macrocyclic quinol-containing ligand enables high catalase activity even with a redox-inactive metal at the expense of the ability to mimic superoxide dismutase. Chem Sci 2023; 14:9910-9922. [PMID: 37736643 PMCID: PMC10510768 DOI: 10.1039/d3sc02398b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/25/2023] [Indexed: 09/23/2023] Open
Abstract
Previously, we found that linear quinol-containing ligands could allow manganese complexes to act as functional mimics of superoxide dismutase (SOD). The redox activity of the quinol enables even Zn(ii) complexes with these ligands to catalyze superoxide degradation. As we were investigating the abilities of manganese and iron complexes with 1,8-bis(2,5-dihydroxybenzyl)-1,4,8,11-tetraazacyclotetradecane (H4qp4) to act as redox-responsive contrast agents for magnetic resonance imaging (MRI), we found evidence that they could also catalyze the dismutation of H2O2. Here, we investigate the antioxidant behavior of Mn(ii), Fe(ii), and Zn(ii) complexes with H4qp4. Although the H4qp4 complexes are relatively poor mimetics of SOD, with only the manganese complex displaying above-baseline catalysis, all three display extremely potent catalase activity. The ability of the Zn(ii) complex to catalyze the degradation of H2O2 demonstrates that the use of a redox-active ligand can enable redox-inactive metals to catalyze the decomposition of reactive oxygen species (ROS) besides superoxide. The results also demonstrate that the ligand framework can tune antioxidant activity towards specific ROS.
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Affiliation(s)
- Sana Karbalaei
- Department of Chemistry and Biochemistry, Auburn University Auburn AL 36849 USA
| | - Alicja Franke
- Department of Chemistry, Ludwig-Maximilians-Universität München 81377 München Germany
| | - Julian Oppelt
- Department of Chemistry, Ludwig-Maximilians-Universität München 81377 München Germany
| | - Tarfi Aziz
- Department of Chemistry and Biochemistry, Auburn University Auburn AL 36849 USA
| | - Aubree Jordan
- Department of Chemistry and Biochemistry, Auburn University Auburn AL 36849 USA
| | - P Raj Pokkuluri
- Department of Chemistry and Biochemistry, Auburn University Auburn AL 36849 USA
| | - Dean D Schwartz
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University Auburn AL 36849 USA
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Moore JL, Oppelt J, Senft L, Franke A, Scheitler A, Dukes MW, Alix HB, Saunders AC, Karbalaei S, Schwartz DD, Ivanović-Burmazović I, Goldsmith CR. Diquinol Functionality Boosts the Superoxide Dismutase Mimicry of a Zn(II) Complex with a Redox-Active Ligand while Maintaining Catalyst Stability and Enhanced Activity in Phosphate Solution. Inorg Chem 2022; 61:19983-19997. [PMID: 36445832 DOI: 10.1021/acs.inorgchem.2c03256] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In the current work, we demonstrate ligand design concepts that significantly improve the superoxide dismutase (SOD) activity of a zinc complex; the catalysis is enhanced when two quinol groups are present in the polydentate ligand. We investigate the mechanism through which the quinols influence the catalysis and determine the impact of entirely removing a chelating group from the original hexadentate ligand. Our results suggest that SOD mimicry with these compounds requires a ligand that coordinates Zn(II) strongly in both its oxidized and reduced forms and that the activity proceeds through Zn(II)-semiquinone complexes. The complex with two quinols displays greatly enhanced catalytic ability, with the activity improving by as much as 450% over a related complex with a single quinol. In the reduced form of the diquinol complex, one quinol appears to coordinate to the zinc much more weakly than the other. We believe that superoxide can more readily displace this portion of the ligand, facilitating its coordination to the metal center and thereby hastening the SOD reactivity. Despite the presence of two redox-active groups that may communicate through intramolecular hydrogen bonding and redox tautomerism, only one quinol undergoes two-electron oxidation to a para-quinone during the catalysis. After the formation of the para-quinone, the remaining quinol deprotonates and binds tightly to the metal, ensuring that the complex remains intact in its oxidized state, thereby maintaining its catalytic ability. The Zn(II) complex with the diquinol ligand is highly unusual for a SOD mimic in that it performs more efficiently in phosphate solution.
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Affiliation(s)
- Jamonica L Moore
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama36849, United States
| | - Julian Oppelt
- Department Chemie, Ludwig- Maximilians Universität (LMU) München, München81377, Germany
| | - Laura Senft
- Department Chemie, Ludwig- Maximilians Universität (LMU) München, München81377, Germany
| | - Alicja Franke
- Department Chemie, Ludwig- Maximilians Universität (LMU) München, München81377, Germany
| | - Andreas Scheitler
- Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Egerlandstr. 1, Erlangen91508, Germany
| | - Meghan W Dukes
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama36849, United States
| | - Haley B Alix
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama36849, United States
| | - Alexander C Saunders
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama36849, United States
| | - Sana Karbalaei
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama36849, United States
| | - Dean D Schwartz
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, Alabama36849, United States
| | | | - Christian R Goldsmith
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama36849, United States
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Copper (II) complexes derived from pyridoxal: Structural correlations, cytotoxic activities, and molecular docking. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120530] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Senft L, Moore JL, Franke A, Fisher KR, Scheitler A, Zahl A, Puchta R, Fehn D, Ison S, Sader S, Ivanović-Burmazović I, Goldsmith CR. Quinol-containing ligands enable high superoxide dismutase activity by modulating coordination number, charge, oxidation states and stability of manganese complexes throughout redox cycling. Chem Sci 2021; 12:10483-10500. [PMID: 34447541 PMCID: PMC8356818 DOI: 10.1039/d1sc02465e] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 07/05/2021] [Indexed: 01/01/2023] Open
Abstract
Reactivity assays previously suggested that two quinol-containing MRI contrast agent sensors for H2O2, [Mn(H2qp1)(MeCN)]2+ and [Mn(H4qp2)Br2], could also catalytically degrade superoxide. Subsequently, [Zn(H2qp1)(OTf)]+ was found to use the redox activity of the H2qp1 ligand to catalyze the conversion of O2˙− to O2 and H2O2, raising the possibility that the organic ligand, rather than the metal, could serve as the redox partner for O2˙− in the manganese chemistry. Here, we use stopped-flow kinetics and cryospray-ionization mass spectrometry (CSI-MS) analysis of the direct reactions between the manganese-containing contrast agents and O2˙− to confirm the activity and elucidate the catalytic mechanism. The obtained data are consistent with the operation of multiple parallel catalytic cycles, with both the quinol groups and manganese cycling through different oxidation states during the reactions with superoxide. The choice of ligand impacts the overall charges of the intermediates and allows us to visualize complementary sets of intermediates within the catalytic cycles using CSI-MS. With the diquinolic H4qp2, we detect Mn(iii)-superoxo intermediates with both reduced and oxidized forms of the ligand, a Mn(iii)-hydroperoxo compound, and what is formally a Mn(iv)-oxo species with the monoquinolate/mono-para-quinone form of H4qp2. With the monoquinolic H2qp1, we observe a Mn(ii)-superoxo ↔ Mn(iii)-peroxo intermediate with the oxidized para-quinone form of the ligand. The observation of these species suggests inner-sphere mechanisms for O2˙− oxidation and reduction that include both the ligand and manganese as redox partners. The higher positive charges of the complexes with the reduced and oxidized forms of H2qp1 compared to those with related forms of H4qp2 result in higher catalytic activity (kcat ∼ 108 M−1 s−1 at pH 7.4) that rivals those of the most active superoxide dismutase (SOD) mimics. The manganese complex with H2qp1 is markedly more stable in water than other highly active non-porphyrin-based and even some Mn(ii) porphyrin-based SOD mimics. Manganese complexes with polydentate quinol-containing ligands are found to catalyze the degradation of superoxide through inner-sphere mechanisms. The redox activity of the ligand stabilizes higher-valent manganese species.![]()
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Affiliation(s)
- Laura Senft
- Department of Chemistry, Ludwig-Maximilian-University Butenandtstr. 5-13 D 81377 Munich Germany
| | - Jamonica L Moore
- Department of Chemistry and Biochemistry, Auburn University Auburn AL 36849 USA
| | - Alicja Franke
- Department of Chemistry, Ludwig-Maximilian-University Butenandtstr. 5-13 D 81377 Munich Germany
| | - Katherine R Fisher
- Department of Chemistry, Ludwig-Maximilian-University Butenandtstr. 5-13 D 81377 Munich Germany
| | - Andreas Scheitler
- Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nuremberg 91058 Erlangen Germany
| | - Achim Zahl
- Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nuremberg 91058 Erlangen Germany
| | - Ralph Puchta
- Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nuremberg 91058 Erlangen Germany
| | - Dominik Fehn
- Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nuremberg 91058 Erlangen Germany
| | - Sidney Ison
- Department of Chemistry and Biochemistry, Auburn University Auburn AL 36849 USA
| | - Safaa Sader
- Department of Chemistry and Biochemistry, Auburn University Auburn AL 36849 USA
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Superoxide dismutase activity enabled by a redox-active ligand rather than metal. Nat Chem 2018; 10:1207-1212. [PMID: 30275506 DOI: 10.1038/s41557-018-0137-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 08/09/2018] [Indexed: 12/23/2022]
Abstract
Reactive oxygen species are integral to many physiological processes. Although their roles are still being elucidated, they seem to be linked to a variety of disorders and may represent promising drug targets. Mimics of superoxide dismutases, which catalyse the decomposition of O2•- to H2O2 and O2, have traditionally used redox-active metals, which are toxic outside of a tightly coordinating ligand. Purely organic antioxidants have also been investigated but generally require stoichiometric, rather than catalytic, doses. Here, we show that a complex of the redox-inactive metal zinc(II) with a hexadentate ligand containing a redox-active quinol can catalytically degrade superoxide, as demonstrated by both reactivity assays and stopped-flow kinetics studies of direct reactions with O2•- and the zinc(II) complex. The observed superoxide dismutase catalysis has an important advantage over previously reported work in that it is hastened, rather than impeded, by the presence of phosphate, the concentration of which is high under physiological conditions.
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Which Is the Most Significant Cause of Aging? Antioxidants (Basel) 2015; 4:793-810. [PMID: 26783959 PMCID: PMC4712935 DOI: 10.3390/antiox4040793] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 11/19/2015] [Accepted: 12/02/2015] [Indexed: 12/19/2022] Open
Abstract
It becomes clearer and clearer that aging is a result of a significant number of causes and it would seem that counteracting one or several of them should not make a significant difference. Taken at face value, this suggests, for example, that free radicals and reactive oxygen species do not play a significant role in aging and that the lifespan of organisms cannot be significantly extended. In this review, I point to the fact that the causes of aging synergize with each other and discuss the implications involved. One implication is that when two or more synergizing causes increase over time, the result of their action increases dramatically; I discuss a simple model demonstrating this. It is reasonable to conclude that this might explain the acceleration of aging and mortality with age. In this regard, the analysis of results and mortality patterns described in studies involving yeasts and Drosophila provides support for this view. Since the causes of aging are synergizing, it is also concluded that none of them is the major one but many including free radicals, etc. play significant roles. It follows that health/lifespan might be significantly extended if we eliminate or even attenuate the increase of a few or even just one of the causes of aging. While the synergism between the causes of aging is the main topic of this review, several related matters are briefly discussed as well.
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Liochev SI. Reflections on the Theories of Aging, of Oxidative Stress, and of Science in General. Is It Time to Abandon the Free Radical (Oxidative Stress) Theory of Aging? Antioxid Redox Signal 2015; 23:187-207. [PMID: 24949668 DOI: 10.1089/ars.2014.5928] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
SIGNIFICANCE Aging and oxidative stress are complex phenomena, and their understanding is of enormous theoretical and practical significance. RECENT ADVANCES Numerous hypotheses and theories that attempt to explain these phenomena have been developed. These hypotheses and theories compete with each other, with each claiming to be the correct one, while significantly contradicting each other. CRITICAL ISSUES It is important to develop a maximally correct theory that may then trigger significant practical breakthroughs. FUTURE DIRECTIONS None of these theories is entirely correct or close enough to the truth. However, most of them contain many correct elements (CE). Finding these CE is possible by analysis of these theories. Once the CE are found, they can be merged by synthesis in a better new theory. An analysis of some of the theories of aging followed by synthesis is attempted.
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Synthesis, Characterization and SOD-Like Activity of Histidine Immobilized Silica Nanoparticles. J Inorg Organomet Polym Mater 2015. [DOI: 10.1007/s10904-015-0239-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Richard PU, Duskey JT, Stolarov S, Spulber M, Palivan CG. New concepts to fight oxidative stress: nanosized three-dimensional supramolecular antioxidant assemblies. Expert Opin Drug Deliv 2015; 12:1527-45. [DOI: 10.1517/17425247.2015.1036738] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Cheng KY, Guo F, Lu JQ, Cao YZ, Wang TC, Yang Q, Xia Q. MnTM-4-PyP modulates endogenous antioxidant responses and protects primary cortical neurons against oxidative stress. CNS Neurosci Ther 2014; 21:435-45. [PMID: 25545542 DOI: 10.1111/cns.12373] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 11/28/2014] [Accepted: 11/28/2014] [Indexed: 12/13/2022] Open
Abstract
AIMS Oxidative stress is a direct cause of injury in various neural diseases. Manganese porphyrins (MnPs), a large category of superoxide dismutase (SOD) mimics, shown universally to have effects in numerous neural disease models in vivo. Given their complex intracellular redox activities, detailed mechanisms underlying the biomedical efficacies are not fully elucidated. This study sought to investigate the regulation of endogenous antioxidant systems by a MnP (MnTM-4-PyP) and its role in the protection against neural oxidative stress. METHODS Primary cortical neurons were treated with MnTM-4-PyP prior to hydrogen peroxide-induced oxidative stress. RESULTS MnTM-4-PyP increased cell viability, reduced intracellular level of reactive oxygen species, inhibited mitochondrial apoptotic pathway, and ameliorated endoplasmic reticulum function. The protein levels and activities of endogenous SODs were elevated, but not those of catalase. SOD2 transcription was promoted in a transcription factor-specific manner. Additionally, we found FOXO3A and Sirt3 levels also increased. These effects were not observed with MnTM-4-PyP alone. CONCLUSION Induction of various levels of endogenous antioxidant responses by MnTM-4-PyP has indispensable functions in its protection for cortical neurons against hydrogen peroxide-induced oxidative stress.
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Affiliation(s)
- Kuo-Yuan Cheng
- Department of Chemical Biology, State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China
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Celic T, Španjol J, Bobinac M, Tovmasyan A, Vukelic I, Reboucas JS, Batinic-Haberle I, Bobinac D. Mn porphyrin-based SOD mimic, MnTnHex-2-PyP(5+), and non-SOD mimic, MnTBAP(3-), suppressed rat spinal cord ischemia/reperfusion injury via NF-κB pathways. Free Radic Res 2014; 48:1426-42. [PMID: 25185063 DOI: 10.3109/10715762.2014.960865] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Herein we have demonstrated that both superoxide dismutase (SOD) mimic, cationic Mn(III) meso-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin (MnTnHex-2-PyP(5+)), and non-SOD mimic, anionic Mn(III) meso-tetrakis(4-carboxylatophenyl)porphyrin (MnTBAP(3-)), protect against oxidative stress caused by spinal cord ischemia/reperfusion via suppression of nuclear factor kappa B (NF-κB) pro-inflammatory pathways. Earlier reports showed that Mn(III) N-alkylpyridylporphyrins were able to prevent the DNA binding of NF-κB in an aqueous system, whereas MnTBAP(3-) was not. Here, for the first time, in a complex in vivo system-animal model of spinal cord injury-a similar impact of MnTBAP(3-), at a dose identical to that of MnTnHex-2-PyP(5+), was demonstrated in NF-κB downregulation. Rats were treated subcutaneously at 1.5 mg/kg starting at 30 min before ischemia/reperfusion, and then every 12 h afterward for either 48 h or 7 days. The anti-inflammatory effects of both Mn porphyrins (MnPs) were demonstrated in the spinal cord tissue at both 48 h and 7 days. The downregulation of NF-κB, a major pro-inflammatory signaling protein regulating astrocyte activation, was detected and found to correlate well with the suppression of astrogliosis (as glial fibrillary acidic protein) by both MnPs. The markers of oxidative stress, lipid peroxidation and protein carbonyl formation, were significantly reduced by MnPs. The favorable impact of both MnPs on motor neurons (Tarlov score and inclined plane test) was assessed. No major changes in glutathione peroxidase- and SOD-like activities were demonstrated, which implies that none of the MnPs acted as SOD mimic. Increasing amount of data on the reactivity of MnTBAP(3-) with reactive nitrogen species (RNS) (.NO/HNO/ONOO(-)) suggests that RNS/MnTBAP(3-)-driven modification of NF-κB protein cysteines may be involved in its therapeutic effects. This differs from the therapeutic efficacy of MnTnHex-2-PyP(5+) which presumably occurs via reactive oxygen species and relates to NF-κB thiol oxidation; the role of RNS cannot be excluded.
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Affiliation(s)
- T Celic
- Department of Anatomy, Faculty of Medicine, University of Rijeka , Rijeka , Croatia
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Liochev SI. Free radicals: how do we stand them? Anaerobic and aerobic free radical (chain) reactions involved in the use of fluorogenic probes and in biological systems. Med Princ Pract 2014; 23:195-203. [PMID: 24356000 PMCID: PMC5586870 DOI: 10.1159/000357120] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 11/07/2013] [Indexed: 01/21/2023] Open
Abstract
Biologically significant conclusions have been based on the use of fluorogenic and luminogenic probes for the detection of reactive species. The basic mechanisms of the processes involved have not been satisfactorily elucidated. In the present work, the mechanism of the enzyme and photosensitized oxidation of NAD(P)H by resorufin is analyzed and appears to involve both aerobic and anaerobic free radical chain reactions. There are two major fallouts of this analysis. Many of the conclusions about the participation of radicals based on the use of probes such as resorufin and Amplex red need reevaluation. It is also concluded that anaerobic free radical reactions may be biologically significant, and the possible existence of enzymatic systems to eliminate certain free radicals is discussed.
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Batinic-Haberle I, Tovmasyan A, Spasojevic I. The complex mechanistic aspects of redox-active compounds, commonly regarded as SOD mimics. ACTA ACUST UNITED AC 2013. [DOI: 10.1515/irm-2013-0004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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