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Ageeva AA, Doktorov AB, Polyakov NE, Leshina TV. Chiral Linked Systems as a Model for Understanding D-Amino Acids Influence on the Structure and Properties of Amyloid Peptides. Int J Mol Sci 2022; 23:ijms23063060. [PMID: 35328481 PMCID: PMC8955658 DOI: 10.3390/ijms23063060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 03/10/2022] [Indexed: 01/27/2023] Open
Abstract
In this review, we provide an illustration of the idea discussed in the literature of using model compounds to study the effect of substitution of L- for D-amino acid residues in amyloid peptides. The need for modeling is due to the inability to study highly disordered peptides by traditional methods (high-field NMR, X-ray). At the same time, the appearance of such peptides, where L-amino acids are partially replaced by D-analogs is one of the main causes of Alzheimer’s disease. The review presents examples of the use diastereomers with L-/D-tryptophan in model process—photoinduced electron transfer (ET) for studying differences in reactivity and structure of systems with L- and D-optical isomers. The combined application of spin effects, including those calculated using the original theory, fluorescence techniques and molecular modeling has demonstrated a real difference in the structure and efficiency of ET in diastereomers with L-/D-tryptophan residues. In addition, the review compared the factors governing chiral inversion in model metallopeptides and Aβ42 amyloid.
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Affiliation(s)
- Aleksandra A. Ageeva
- Voevodsky Institute of Chemical Kinetics and Combustion, 630090 Novosibirsk, Russia; (A.A.A.); (N.E.P.); (T.V.L.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Alexander B. Doktorov
- Voevodsky Institute of Chemical Kinetics and Combustion, 630090 Novosibirsk, Russia; (A.A.A.); (N.E.P.); (T.V.L.)
- Correspondence: author:
| | - Nikolay E. Polyakov
- Voevodsky Institute of Chemical Kinetics and Combustion, 630090 Novosibirsk, Russia; (A.A.A.); (N.E.P.); (T.V.L.)
| | - Tatyana V. Leshina
- Voevodsky Institute of Chemical Kinetics and Combustion, 630090 Novosibirsk, Russia; (A.A.A.); (N.E.P.); (T.V.L.)
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2
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Spencer P, Ye Q, Song L, Parthasarathy R, Boone K, Misra A, Tamerler C. Threats to adhesive/dentin interfacial integrity and next generation bio-enabled multifunctional adhesives. J Biomed Mater Res B Appl Biomater 2019; 107:2673-2683. [PMID: 30895695 PMCID: PMC6754319 DOI: 10.1002/jbm.b.34358] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 02/07/2019] [Accepted: 02/20/2019] [Indexed: 12/27/2022]
Abstract
Nearly 100 million of the 170 million composite and amalgam restorations placed annually in the United States are replacements for failed restorations. The primary reason both composite and amalgam restorations fail is recurrent decay, for which composite restorations experience a 2.0-3.5-fold increase compared to amalgam. Recurrent decay is a pernicious problem-the standard treatment is replacement of defective composites with larger restorations that will also fail, initiating a cycle of ever-larger restorations that can lead to root canals, and eventually, to tooth loss. Unlike amalgam, composite lacks the inherent capability to seal discrepancies at the restorative material/tooth interface. The low-viscosity adhesive that bonds the composite to the tooth is intended to seal the interface, but the adhesive degrades, which can breach the composite/tooth margin. Bacteria and bacterial by-products such as acids and enzymes infiltrate the marginal gaps and the composite's inability to increase the interfacial pH facilitates cariogenic and aciduric bacterial outgrowth. Together, these characteristics encourage recurrent decay, pulpal damage, and composite failure. This review article examines key biological and physicochemical interactions involved in the failure of composite restorations and discusses innovative strategies to mitigate the negative effects of pathogens at the adhesive/dentin interface. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2466-2475, 2019.
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Affiliation(s)
- Paulette Spencer
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
- Department of Mechanical Engineering, University of Kansas,1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Qiang Ye
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Linyong Song
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Ranganathan Parthasarathy
- Department of Civil Engineering, Tennessee State University, 3500 John A Merritt Blvd, Nashville, TN 37209, USA
| | - Kyle Boone
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Anil Misra
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
- Department of Civil Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Candan Tamerler
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
- Department of Mechanical Engineering, University of Kansas,1530 W. 15th Street, Lawrence, KS 66045-7609, USA
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3
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Domergue J, Pécaut J, Proux O, Lebrun C, Gateau C, Le Goff A, Maldivi P, Duboc C, Delangle P. Mononuclear Ni(II) Complexes with a S3O Coordination Sphere Based on a Tripodal Cysteine-Rich Ligand: pH Tuning of the Superoxide Dismutase Activity. Inorg Chem 2019; 58:12775-12785. [PMID: 31545024 DOI: 10.1021/acs.inorgchem.9b01686] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The superoxide dismutase (SOD) activity of mononuclear NiII complexes, whose structures are inspired by the NiSOD, has been investigated. They have been designed with a sulfur-rich pseudopeptide ligand, derived from nitrilotriacetic acid (NTA), where the three acid functions are grafted with cysteines (L3S). Two mononuclear complexes, which exist in pH-dependent proportions, have been fully characterized by a combination of spectroscopic techniques including 1H NMR, UV-vis, circular dichroism, and X-ray absorption spectroscopy, together with theoretical calculations. They display similar square-planar S3O coordination, with the three thiolates of the three cysteine moieties from L3S coordinated to the NiII ion, together with either a water molecule at physiological pH, as [NiL3S(OH2)]-, or a hydroxo ion in more basic conditions, as [NiL3S(OH)]2-. The 1H NMR study has revealed that contrary to the hydroxo ligand, the bound water molecule is labile. The cyclic voltammogram of both complexes displays an irreversible one-electron oxidation process assigned to the NiII/NiIII redox system with Epa = 0.48 and 0.31 V versus SCE for NiL3S(OH2) and NiL3S(OH), respectively. The SOD activity of both complexes has been tested. On the basis of the xanthine oxidase assay, an IC50 of about 1 μM has been measured at pH 7.4, where NiL3S(OH2) is mainly present (93% of the NiII species), while the IC50 is larger than 100 μM at pH 9.6, where NiL3S(OH) is the major species (92% of the NiII species). Interestingly, only NiL3S(OH2) displays SOD activity, suggesting that the presence of a labile ligand is required. The SOD activity has been also evaluated under catalytic conditions at pH 7.75, where the ratio between NiL3S(OH2)/ NiL3S(OH) is about (86:14), and a rate constant, kcat = 1.8 × 105 M-1 s-1, has been measured. NiL3S(OH2) is thus the first low-molecular weight, synthetic, bioinspired Ni complex that displays catalytic SOD activity in water at physiological pH, although it does not contain any N-donor ligand in its first coordination sphere, as in the NiSOD. Overall, the data show that a key structural feature is the presence of a labile ligand in the coordination sphere of the NiII ion.
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Affiliation(s)
- Jérémy Domergue
- Univ. Grenoble Alpes, CNRS, DCM , 38000 Grenoble , France.,Univ. Grenoble Alpes, CEA, CNRS, IRIG, SYMMES , 38000 Grenoble , France
| | - Jacques Pécaut
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, SYMMES , 38000 Grenoble , France
| | - Olivier Proux
- Univ. Grenoble Alpes, CNRS, OSUG , 38000 Grenoble , France
| | - Colette Lebrun
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, SYMMES , 38000 Grenoble , France
| | - Christelle Gateau
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, SYMMES , 38000 Grenoble , France
| | - Alan Le Goff
- Univ. Grenoble Alpes, CNRS, DCM , 38000 Grenoble , France
| | - Pascale Maldivi
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, SYMMES , 38000 Grenoble , France
| | - Carole Duboc
- Univ. Grenoble Alpes, CNRS, DCM , 38000 Grenoble , France
| | - Pascale Delangle
- Univ. Grenoble Alpes, CEA, CNRS, IRIG, SYMMES , 38000 Grenoble , France
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McCabe JW, Vangala R, Angel LA. Binding Selectivity of Methanobactin from Methylosinus trichosporium OB3b for Copper(I), Silver(I), Zinc(II), Nickel(II), Cobalt(II), Manganese(II), Lead(II), and Iron(II). JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:2588-2601. [PMID: 28856622 DOI: 10.1007/s13361-017-1778-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/03/2017] [Accepted: 08/04/2017] [Indexed: 05/22/2023]
Abstract
Methanobactin (Mb) from Methylosinus trichosporium OB3b is a member of a class of metal binding peptides identified in methanotrophic bacteria. Mb will selectively bind and reduce Cu(II) to Cu(I), and is thought to mediate the acquisition of the copper cofactor for the enzyme methane monooxygenase. These copper chelating properties of Mb make it potentially useful as a chelating agent for treatment of diseases where copper plays a role including Wilson's disease, cancers, and neurodegenerative diseases. Utilizing traveling wave ion mobility-mass spectrometry (TWIMS), the competition for the Mb copper binding site from Ag(I), Pb(II), Co(II), Fe(II), Mn(II), Ni(II), and Zn(II) has been determined by a series of metal ion titrations, pH titrations, and metal ion displacement titrations. The TWIMS analyses allowed for the explicit identification and quantification of all the individual Mb species present during the titrations and measured their collision cross-sections and collision-induced dissociation patterns. The results showed Ag(I) and Ni(II) could irreversibly bind to Mb and not be effectively displaced by Cu(I), whereas Ag(I) could also partially displace Cu(I) from the Mb complex. At pH ≈ 6.5, the Mb binding selectivity follows the order Ag(I)≈Cu(I)>Ni(II)≈Zn(II)>Co(II)>>Mn(II)≈Pb(II)>Fe(II), and at pH 7.5 to 10.4 the order is Ag(I)>Cu(I)>Ni(II)>Co(II)>Zn(II)>Mn(II)≈Pb(II)>Fe(II). Breakdown curves of the disulfide reduced Cu(I) and Ag(I) complexes showed a correlation existed between their relative stability and their compact folded structure indicated by their CCS. Fluorescence spectroscopy, which allowed the determination of the binding constant, compared well with the TWIMS analyses, with the exception of the Ni(II) complex. Graphical abstract ᅟ.
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Affiliation(s)
- Jacob W McCabe
- Department of Chemistry, Texas A&M University-Commerce, Commerce, TX, 75428, USA
| | - Rajpal Vangala
- Department of Chemistry, Texas A&M University-Commerce, Commerce, TX, 75428, USA
| | - Laurence A Angel
- Department of Chemistry, Texas A&M University-Commerce, Commerce, TX, 75428, USA.
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5
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Truong PT, Gale EM, Dzul SP, Stemmler TL, Harrop TC. Steric Enforcement about One Thiolate Donor Leads to New Oxidation Chemistry in a NiSOD Model Complex. Inorg Chem 2017; 56:7761-7780. [PMID: 28459242 DOI: 10.1021/acs.inorgchem.7b00485] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ni-containing superoxide dismutase (NiSOD) represents an unusual member of the SOD family due to the presence of oxygen-sensitive Ni-SCys bonds at its active site. Reported in this account is the synthesis and properties of the NiII complex of the N3S2 ligand [N3S2Me2]3- ([N3S2Me2]3- = deprotonated form of 2-((2-mercapto-2-methylpropyl)(pyridin-2-ylmethyl)amino)-N-(2-mercaptoethyl)acetamide), namely Na[Ni(N3S2Me2)] (2), as a NiSOD model that features sterically robust gem-(CH3)2 groups on the thiolate α-C positioned trans to the carboxamide. The crystal structure of 2, coupled with spectroscopic measurements from 1H NMR, X-ray absorption, IR, UV-vis, and mass spectrometry (MS), reveal a planar NiII (S = 0) ion coordinated by only the N2S2 basal donors of the N3S2 ligand. While the structure and spectroscopic properties of 2 resemble those of NiSODred and other models, the asymmetric S ligands open up new reaction paths upon chemical oxidation. One unusual oxidation product is the planar NiII-N3S complex [Ni(Lox)] (5; Lox = 2-(5,5-dimethyl-2-(pyridin-2-yl)thiazolidin-3-yl)-N-(2-mercaptoethyl)acetamide), where two-electron oxidation takes place at the substituted thiolate and py-CH2 carbon to generate a thiazolidine heterocycle. Electrochemical measurements of 2 reveal irreversible events wholly consistent with thiolate redox, which were identified by comparison to the ZnII complex Na[Zn(N3S2Me2)] (3). Although no reaction is observed between 2 and azide, reaction of 2 with superoxide produces multiple products on the basis of UV-vis and MS data, one of which is 5. Density functional theory (DFT) computations suggest that the HOMO in 2 is π* with primary contributions from Ni-dπ/S-pπ orbitals. These contributions can be modulated and biased toward Ni when electron-withdrawing groups are placed on the thiolate α-C. Analysis of the oxidized five-coordinate species 2ox* by DFT reveal a singly occupied spin-up (α) MO that is largely thiolate based, which supports the proposed NiIII-thiolate/NiII-thiyl radical intermediates that ultimately yield 5 and other products.
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Affiliation(s)
- Phan T Truong
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia , 140 Cedar Street, Athens, Georgia 30602, United States
| | - Eric M Gale
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia , 140 Cedar Street, Athens, Georgia 30602, United States
| | - Stephen P Dzul
- Departments of Pharmaceutical Sciences, Biochemistry and Molecular Biology, Wayne State University , Detroit, Michigan 48201, United States
| | - Timothy L Stemmler
- Departments of Pharmaceutical Sciences, Biochemistry and Molecular Biology, Wayne State University , Detroit, Michigan 48201, United States
| | - Todd C Harrop
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia , 140 Cedar Street, Athens, Georgia 30602, United States
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6
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McNiff ML, Chadwick JS. Metal-bound claMP Tag inhibits proteolytic cleavage. Protein Eng Des Sel 2017; 30:467-475. [PMID: 28541524 DOI: 10.1093/protein/gzx030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 05/05/2017] [Indexed: 11/13/2022] Open
Abstract
Biologics can be an improvement to small molecule drugs, providing high specificity for an identified target, lowering toxicity and limiting side effects. To achieve effective delivery, the biologic must have sufficient time to reach the target tissue. A prolonged half-life in the circulating environment is desired, but often serum stability is limited by proteases. Proteolysis in the serum causes degradation and inactivation as the biologic is fragmented and more rapidly cleared from the body. To improve the circulating half-life, large, hydrophilic polymers may be conjugated or stable fusion tags may be engineered to increase the effective size of the peptide and to hinder degradation by proteases. Improved resistance to proteases is essential for effective delivery. Here, a proof of concept study is presented using a metal-binding tripeptide tag known as the claMP Tag to create an inline conjugate and the ability of the tag to inhibit proteolysis was examined.
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Affiliation(s)
- Michaela L McNiff
- Department of Pharmaceutical Chemistry, University of Kansas, 2093 Constant Ave, Lawrence, KS 66047
| | - Jennifer S Chadwick
- Department of Pharmaceutical Chemistry, University of Kansas, 2093 Constant Ave, Lawrence, KS 66047.,BioAnalytix Inc., 790 Memorial Dr., Cambridge, MA 02139
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7
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Schöneich C. Sulfur Radical-Induced Redox Modifications in Proteins: Analysis and Mechanistic Aspects. Antioxid Redox Signal 2017; 26:388-405. [PMID: 27288212 DOI: 10.1089/ars.2016.6779] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
SIGNIFICANCE The sulfur-containing amino acids cysteine (Cys) and methionine (Met) are prominent protein targets of redox modification during conditions of oxidative stress. Here, two-electron pathways have received widespread attention, in part due to their role in signaling processes. However, Cys and Met are equally prone to one-electron pathways, generating intermediary radicals and/or radial ions. These radicals/radical ions can generate various reaction products that are not commonly monitored in redox proteomic studies, but they may be relevant for the fate of proteins during oxidative stress. Recent Advances: Time-resolved kinetic studies and product analysis have expanded our mechanistic understanding of radical reaction pathways of sulfur-containing amino acids. These reactions are now studied in some detail for Met and Cys in proteins, and homocysteine (Hcy) chemically linked to proteins, and the role of protein radical reactions in physiological processes is evolving. CRITICAL ISSUES Radical-derived products from Cys, Hcy, and Met can react with additional amino acids in proteins, leading to secondary protein modifications, which are potentially remote from initial points of radical attack. These products may contain intra- and intermolecular cross-links, which may lead to protein aggregation. Protein sequence and conformation will have a significant impact on the formation of such products, and a thorough understanding of reaction mechanisms and specifically how protein structure influences reaction pathways will be critical for identification and characterization of novel reaction products. FUTURE DIRECTIONS Future studies must evaluate the biological significance of novel reaction products that are derived from radical reactions of sulfur-containing amino acids. Antioxid. Redox Signal. 26, 388-405.
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Affiliation(s)
- Christian Schöneich
- Department of Pharmaceutical Chemistry, The University of Kansas , Lawrence, Kansas
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8
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Steiner RA, Dzul SP, Stemmler TL, Harrop TC. Synthesis and Speciation-Dependent Properties of a Multimetallic Model Complex of NiSOD That Exhibits Unique Hydrogen-Bonding. Inorg Chem 2017; 56:2849-2862. [PMID: 28212040 DOI: 10.1021/acs.inorgchem.6b02997] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The complex Na3[{NiII(nmp)}3S3BTAalk)] (1) (nmp2- = deprotonated form of N-(2-mercaptoethyl)picolinamide; H3S3BTAalk = N1,N3,N5-tris(2-mercaptoethyl)benzene-1,3,5-tricarboxamide, where H = dissociable protons), supported by the thiolate-benzenetricarboxamide scaffold (S3BTAalk), has been synthesized as a trimetallic model of nickel-containing superoxide dismutase (NiSOD). X-ray absorption spectroscopy (XAS) and 1H NMR measurements on 1 indicate that the NiII centers are square-planar with N2S2 coordination, and Ni-N and Ni-S distances of 1.95 and 2.16 Å, respectively. Additional evidence from IR indicates the presence of H-bonds in 1 from the approximately -200 cm-1 shift in νNH from free ligand. The presence of H-bonds allows for speciation that is temperature-, concentration-, and solvent-dependent. In unbuffered water and at low temperature, a dimeric complex (1A; λ = 410 nm) that aggregates through intermolecular NH···O═C bonds of BTA units is observed. Dissolution of 1 in pH 7.4 buffer or in unbuffered water at temperatures above 50 °C results in monomeric complex (1M; λ = 367 nm) linked through intramolecular NH···S bonds. DFT computations indicate a low energy barrier between 1A and 1M with nearly identical frontier MOs and Ni-ligand metrics. Notably, 1A and 1M exhibit remarkable stability in protic solvents such as MeOH and H2O, in stark contrast to monometallic [NiII(nmp)(SR)]- complexes. The reactivity of 1 with excess O2, H2O2, and O2•- is species-dependent. IR and UV-vis reveal that 1A in MeOH reacts with excess O2 to yield an S-bound sulfinate, but does not react with O2•-. In contrast, 1M is stable to O2 in pH 7.4 buffer, but reacts with O2•- to yield a putative [NiII(nmp)(O2)]- complex from release of the BTA-thiolate based on EPR.
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Affiliation(s)
- Ramsey A Steiner
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia , 140 Cedar St, Athens, Georgia 30602, United States
| | - Stephen P Dzul
- Departments of Pharmaceutical Sciences, and Biochemistry and Molecular Biology, Wayne State University , Detroit, Michigan 48201, United States
| | - Timothy L Stemmler
- Departments of Pharmaceutical Sciences, and Biochemistry and Molecular Biology, Wayne State University , Detroit, Michigan 48201, United States
| | - Todd C Harrop
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia , 140 Cedar St, Athens, Georgia 30602, United States
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9
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Mechanistic investigations of matrix metalloproteinase-8 inhibition by metal abstraction peptide. Biointerphases 2016; 11:021006. [PMID: 27129919 DOI: 10.1116/1.4948340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The mechanism of matrix metalloproteinase-8 (MMP-8) inhibition was investigated using ellipsometric measurements of the interaction of MMP-8 with a surface bound peptide inhibitor, tether-metal abstraction peptide (MAP), bound to self-assembled monolayer films. MMP-8 is a collagenase whose activity and dysregulation have been implicated in a number of disease states, including cancer metastasis, diabetic neuropathy, and degradation of biomedical reconstructions, including dental restorations. Regulation of activity of MMP-8 and other matrix metalloproteinases is thus a significant, but challenging, therapeutic target. Strong inhibition of MMP-8 activity has recently been achieved via the small metal binding peptide tether-MAP. Here, the authors elucidate the mechanism of this inhibition and demonstrate that it occurs through the direct interaction of the MAP Tag and the Zn(2+) binding site in the MMP-8 active site. This enhanced understanding of the mechanism of inhibition will allow the design of more potent inhibitors as well as assays important for monitoring critical MMP levels in disease states.
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10
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McNiff ML, Haynes EP, Dixit N, Gao FP, Laurence JS. Thioredoxin fusion construct enables high-yield production of soluble, active matrix metalloproteinase-8 (MMP-8) in Escherichia coli. Protein Expr Purif 2016; 122:64-71. [PMID: 26923061 DOI: 10.1016/j.pep.2016.02.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/08/2016] [Accepted: 02/19/2016] [Indexed: 01/01/2023]
Abstract
Matrix metalloproteinases (MMPs) are crucial proteases in maintaining the health and integrity of many tissues, however their dysregulation often facilitates disease progression. In disease states these remodeling and repair functions support, for example, metastasis of cancer by both loosening the matrix around tumors to enable cellular invasion and by affecting proliferation and apoptosis, and they promote degradation of biological restorations by weakening the substrate to which the restoration is attached. As such, MMPs are important therapeutic targets. MMP-8 participates in cancer, arthritis, asthma and failure of dental fillings. MMP-8 differs from other MMPs in that it has an insertion that enlarges its active site. To elucidate the unique features of MMP-8 and develop selective inhibitors to this therapeutic target, a stable and active form of the enzyme is needed. MMP-8 has been difficult to express at high yield in a soluble, active form. Typically recombinant MMPs accumulate in inclusion bodies and complex methods are applied to refold and purify protein in acceptable yield. Presented here is a streamlined approach to produce in Escherichia coli a soluble, active, stable MMP-8 fusion protein in high yield. This fusion shows much greater retention of activity when stored refrigerated without glycerol. A variant of this construct that contains the metal binding claMP Tag was also examined to demonstrate the ability to use this tag with a metalloprotein. SDS-PAGE, densitometry, mass spectrometry, circular dichroism spectroscopy and an activity assay were used to analyze the chemical integrity and function of the enzyme.
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Affiliation(s)
- M L McNiff
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, KS 66047, United States
| | - E P Haynes
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, KS 66047, United States
| | - N Dixit
- Bioengineering Research Center, The University of Kansas, Lawrence, KS 66045, United States
| | - F P Gao
- Protein Production Group, The University of Kansas, Lawrence, KS 66047, United States
| | - J S Laurence
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, KS 66047, United States.
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11
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Broering EP, Dillon S, Gale EM, Steiner RA, Telser J, Brunold TC, Harrop TC. Accessing Ni(III)-thiolate versus Ni(II)-thiyl bonding in a family of Ni-N2S2 synthetic models of NiSOD. Inorg Chem 2015; 54:3815-28. [PMID: 25835183 PMCID: PMC4630978 DOI: 10.1021/ic503124f] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Superoxide dismutase (SOD) catalyzes the disproportionation of superoxide (O2(• -)) into H2O2 and O2(g) by toggling through different oxidation states of a first-row transition metal ion at its active site. Ni-containing SODs (NiSODs) are a distinct class of this family of metalloenzymes due to the unusual coordination sphere that is comprised of mixed N/S-ligands from peptide-N and cysteine-S donor atoms. A central goal of our research is to understand the factors that govern reactive oxygen species (ROS) stability of the Ni-S(Cys) bond in NiSOD utilizing a synthetic model approach. In light of the reactivity of metal-coordinated thiolates to ROS, several hypotheses have been proffered and include the coordination of His1-Nδ to the Ni(II) and Ni(III) forms of NiSOD, as well as hydrogen bonding or full protonation of a coordinated S(Cys). In this work, we present NiSOD analogues of the general formula [Ni(N2S)(SR')](-), providing a variable location (SR' = aryl thiolate) in the N2S2 basal plane coordination sphere where we have introduced o-amino and/or electron-withdrawing groups to intercept an oxidized Ni species. The synthesis, structure, and properties of the NiSOD model complexes (Et4N)[Ni(nmp)(SPh-o-NH2)] (2), (Et4N)[Ni(nmp)(SPh-o-NH2-p-CF3)] (3), (Et4N)[Ni(nmp)(SPh-p-NH2)] (4), and (Et4N)[Ni(nmp)(SPh-p-CF3)] (5) (nmp(2-) = dianion of N-(2-mercaptoethyl)picolinamide) are reported. NiSOD model complexes with amino groups positioned ortho to the aryl-S in SR' (2 and 3) afford oxidized species (2(ox) and 3(ox)) that are best described as a resonance hybrid between Ni(III)-SR and Ni(II)-(•)SR based on ultraviolet-visible (UV-vis), magnetic circular dichroism (MCD), and electron paramagnetic resonance (EPR) spectroscopies, as well as density functional theory (DFT) calculations. The results presented here, demonstrating the high percentage of S(3p) character in the highest occupied molecular orbital (HOMO) of the four-coordinate reduced form of NiSOD (NiSODred), suggest that the transition from NiSODred to the five-coordinate oxidized form of NiSOD (NiSODox) may go through a four-coordinate Ni-(•)S(Cys) (NiSODox-Hisoff) that is stabilized by coordination to Ni(II).
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Affiliation(s)
- Ellen P. Broering
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
| | - Stephanie Dillon
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Eric M. Gale
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
| | - Ramsey A. Steiner
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, 430 South Michigan Avenue, Chicago, Illinois 60605, United States
| | - Thomas C. Brunold
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Todd C. Harrop
- Department of Chemistry and Center for Metalloenzyme Studies, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
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12
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Mills BJ, Laurence JS. Stability analysis of an inline peptide-based conjugate for metal delivery: nickel(II)-claMP Tag epidermal growth factor as a model system. J Pharm Sci 2014; 104:416-23. [PMID: 25212829 DOI: 10.1002/jps.24132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 06/11/2014] [Accepted: 07/30/2014] [Indexed: 01/25/2023]
Abstract
Metals are a key component of many diagnostic imaging and biotechnology applications, and the majority of cancer patients receive a platinum-based drug as part of their treatment. Significant effort has been devoted to developing tight binding synthetic chelators to enable effective targeted delivery of metal-based conjugates, with most successes involving lanthanides rather than transition metals for diagnostic imaging. Chemical conjugation modifies the protein's properties and generates a heterogeneous mixture of products. Chelator attachment is typically carried out by converting the amino group on lysines to an amide, which can impact the stability and solubility of the targeting protein and these properties vary among the set of individual conjugate species. Site-specific attachment is sought to reduce complexity and control stability. Here, the metal abstraction peptide technology was applied to create the claMP Tag, an inline platform for generating site-specific conjugates involving transition metals. The claMP Tag was genetically encoded into epidermal growth factor (EGF) and loaded with nickel(II) as a model system to demonstrate that the tag within the homogeneous inline conjugate presents sufficient solution stability to enable biotechnology applications. The structure and disulfide network of the protein and chemical stability of the claMP Tag and EGF components were characterized.
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Affiliation(s)
- Brittney J Mills
- Department of Chemistry, The University of Kansas, Lawrence, Kansas, 66045
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13
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Chatterjee SK, Maji RC, Barman SK, Olmstead MM, Patra AK. Hexacoordinate nickel(II)/(III) complexes that mimic the catalytic cycle of nickel superoxide dismutase. Angew Chem Int Ed Engl 2014; 53:10184-9. [PMID: 25056843 DOI: 10.1002/anie.201404133] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 06/03/2014] [Indexed: 11/07/2022]
Abstract
A functional model complex of nickel superoxide dismutase (NiSOD) with a non-peptide ligand which mimics the full catalytic cycle of NiSOD is unknown. Similarly, it has not been fully elucidated whether NiSOD activity is a result of an outer- or inner-sphere electron-transfer mechanism. With this in mind, two octahedral nickel(II)/(III) complexes of a bis-tridentate N2 S donor carboxamide ligand, N-2-phenylthiophenyl-2'-pyridinecarboxamide (HL(Ph)), have been synthesized, structurally characterized, and their SOD activities examined. These complexes mimic the full catalytic cycle of NiSOD. Electrochemical experiments support an outer-sphere electron-transfer mechanism for their SOD activity.
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Affiliation(s)
- Sudip K Chatterjee
- Department of Chemistry, National Institute of Technology Durgapur, Mahatma Gandhi Avenue, Durgapur 713 209 (WB) (India)
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14
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Chatterjee SK, Maji RC, Barman SK, Olmstead MM, Patra AK. Hexacoordinate Nickel(II)/(III) Complexes that Mimic the Catalytic Cycle of Nickel Superoxide Dismutase. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201404133] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Nakane D, Wasada-Tsutsui Y, Funahashi Y, Hatanaka T, Ozawa T, Masuda H. A Novel Square-Planar Ni(II) Complex with an Amino—Carboxamido—Dithiolato-Type Ligand as an Active-Site Model of NiSOD. Inorg Chem 2014; 53:6512-23. [DOI: 10.1021/ic402574d] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Daisuke Nakane
- Department
of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555, Japan
| | - Yuko Wasada-Tsutsui
- Department
of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555, Japan
| | - Yasuhiro Funahashi
- Department
of Chemistry, Graduate School of Science, Osaka University, 1-1
Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Tsubasa Hatanaka
- Department
of Chemistry, Graduate School of Science, Osaka University, 1-1
Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Tomohiro Ozawa
- Department
of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555, Japan
| | - Hideki Masuda
- Department
of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466-8555, Japan
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16
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Dixit N, Settle JK, Ye Q, Berrie CL, Spencer P, Laurence JS. Grafting MAP peptide to dental polymer inhibits MMP-8 activity. J Biomed Mater Res B Appl Biomater 2014; 103:324-31. [PMID: 24889674 DOI: 10.1002/jbm.b.33205] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 04/15/2014] [Accepted: 04/29/2014] [Indexed: 11/06/2022]
Abstract
Matrix metalloproteinases (MMPs) are a class of zinc and calcium-dependent endopeptidases responsible for degrading extracellular matrix (ECM) components. Their activity is critical for both normal biological function and pathological processes (Dejonckheere et al., Cytokine Growth Factor Rev 2011;22:73-81). In dental restorations, the release and subsequent acid activation of MMPs contributes to premature failure. In particular, MMP-8 accelerates degradation by cleaving the collagen matrix within the dentin substrate in incompletely infiltrated aged bonded dentin (Buzalaf et al., Adv Dent Res 2012;24:72-76), hastening the need for replacement of restorations. Therefore, development of a dental adhesive that better resists MMP-8 activity is of significant interest. We hypothesize that modification of the polymer surface with an inhibitor would disable MMP-8 activity. Here, we identify the metal abstraction peptide (MAP) as an inhibitor of MMP-8 and demonstrate that tethering MAP to methacrylate polymers effectively inhibits catalysis. Our findings indicate complete inhibition of MMP-8 is achievable using a grafting approach. This strategy has potential to improve longevity of dental adhesives and other polymers and enable rational design of a new generation of biocompatible materials.
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Affiliation(s)
- Namrata Dixit
- Bioengineering Research Center, University of Kansas, Lawrence, Kansas, 66045-7609
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17
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Mills BJ, Mu Q, Krause ME, Laurence JS. claMP Tag: a versatile inline metal-binding platform based on the metal abstraction peptide. Bioconjug Chem 2014; 25:1103-11. [PMID: 24807049 PMCID: PMC4215913 DOI: 10.1021/bc500115h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Molecularly
targeted research and diagnostic tools are essential
to advancing understanding and detection of many diseases. Metals
often impart the desired functionality to these tools, and conjugation
of high-affinity chelators to proteins is carried out to enable targeted
delivery of the metal. This approach has been much more effective
with large lanthanide series metals than smaller transition metals.
Because chemical conjugation requires additional processing and purification
steps and yields a heterogeneous mixture of products, inline incorporation
of a peptide tag capable of metal binding is a highly preferable alternative.
Development of a transition metal binding tag would provide opportunity
to greatly expand metal-based analyses. The metal abstraction peptide
(MAP) sequence was genetically engineered into recombinant protein
to generate the claMP Tag. The effects of this tag
on recombinant epidermal growth factor (EGF) protein expression, disulfide
bond formation, tertiary structural integrity, and transition metal
incorporation using nickel were examined to confirm the viability
of utilizing the MAP sequence to generate linker-less metal conjugates.
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Affiliation(s)
- Brittney J Mills
- Department of Chemistry, The University of Kansas , Lawrence, Kansas 66045, United States
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18
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Broering EP, Truong PT, Gale EM, Harrop TC. Synthetic Analogues of Nickel Superoxide Dismutase: A New Role for Nickel in Biology. Biochemistry 2012; 52:4-18. [DOI: 10.1021/bi3014533] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ellen P. Broering
- Department
of Chemistry and Center for Metalloenzyme
Studies, The University of Georgia, 1001
Cedar Street, Athens, Georgia 30602, United States
| | - Phan T. Truong
- Department
of Chemistry and Center for Metalloenzyme
Studies, The University of Georgia, 1001
Cedar Street, Athens, Georgia 30602, United States
| | - Eric M. Gale
- Department
of Chemistry and Center for Metalloenzyme
Studies, The University of Georgia, 1001
Cedar Street, Athens, Georgia 30602, United States
| | - Todd C. Harrop
- Department
of Chemistry and Center for Metalloenzyme
Studies, The University of Georgia, 1001
Cedar Street, Athens, Georgia 30602, United States
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19
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Krause ME, Glass AM, Jackson TA, Laurence JS. Embedding the Ni-SOD mimetic Ni-NCC within a polypeptide sequence alters the specificity of the reaction pathway. Inorg Chem 2012; 52:77-83. [PMID: 23214928 DOI: 10.1021/ic301175f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The unique metal abstracting peptide asparagine-cysteine-cysteine (NCC) binds nickel in a square planar 2N:2S geometry and acts as a mimic of the enzyme nickel superoxide dismutase (Ni-SOD). The Ni-NCC tripeptide complex undergoes rapid, site-specific chiral inversion to dld-NCC in the presence of oxygen. Superoxide scavenging activity increases proportionally with the degree of chiral inversion. Characterization of the NCC sequence within longer peptides with absorption, circular dichroism (CD), and magnetic CD (MCD) spectroscopies and mass spectrometry (MS) shows that the geometry of metal coordination is maintained, though the electronic properties of the complex are varied to a small extent because of bis-amide, rather than amine/amide, coordination. In addition, both Ni-tripeptide and Ni-pentapeptide complexes have charges of -2. This study demonstrates that the chiral inversion chemistry does not occur when NCC is embedded in a longer polypeptide sequence. Nonetheless, the superoxide scavenging reactivity of the embedded Ni-NCC module is similar to that of the chirally inverted tripeptide complex, which is consistent with a minor change in the reduction potential for the Ni-pentapeptide complex. Together, this suggests that the charge of the complex could affect the SOD activity as much as a change in the primary coordination sphere. In Ni-NCC and other Ni-SOD mimics, changes in chirality, superoxide scavenging activity, and oxidation of the peptide itself all depend on the presence of dioxygen or its reduced derivatives (e.g., superoxide), and the extent to which each of these distinct reactions occurs is ruled by electronic and steric effects that emenate from the organization of ligands around the metal center.
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Affiliation(s)
- Mary E Krause
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, United States
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20
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Shaw WJ. The Outer-Coordination Sphere: Incorporating Amino Acids and Peptides as Ligands for Homogeneous Catalysts to Mimic Enzyme Function. CATALYSIS REVIEWS-SCIENCE AND ENGINEERING 2012. [DOI: 10.1080/01614940.2012.679453] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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21
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Glass AM, Krause ME, Laurence JS, Jackson TA. Controlling the chiral inversion reaction of the metallopeptide Ni-asparagine-cysteine-cysteine with dioxygen. Inorg Chem 2012; 51:10055-63. [PMID: 22928993 DOI: 10.1021/ic301717q] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Synthetically generated metallopeptides have the potential to serve a variety of roles in biotechnology applications, but the use of such systems is often hampered by the inability to control secondary reactions. We have previously reported that the Ni(II) complex of the tripeptide LLL-asparagine-cysteine-cysteine, LLL-Ni(II)-NCC, undergoes metal-facilitated chiral inversion to dld-Ni(II)-NCC, which increases the observed superoxide scavenging activity. However, the mechanism for this process remained unexplored. Electronic absorption and circular dichroism studies of the chiral inversion reaction of Ni(II)-NCC reveal a unique dependence on dioxygen. Specifically, in the absence of dioxygen, the chiral inversion is not observed, even at elevated pH, whereas the addition of O(2) initiates this reactivity and concomitantly generates superoxide. Scavenging experiments using acetaldehyde are indicative of the formation of carbanion intermediates, demonstrating that inversion takes place by deprotonation of the alpha carbons of Asn1 and Cys3. Together, these data are consistent with the chiral inversion being dependent on the formation of a Ni(III)-NCC intermediate from Ni(II)-NCC and O(2). The data further suggest that the anionic thiolate and amide ligands in Ni(II)-NCC inhibit Cα-H deprotonation for the Ni(II) oxidation state, leading to a stable complex in the absence of O(2). Together, these results offer insights into the factors controlling reactivity in synthetic metallopeptides.
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Affiliation(s)
- Amanda M Glass
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
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22
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Gale EM, Cowart DM, Scott RA, Harrop TC. Dipeptide-based models of nickel superoxide dismutase: solvent effects highlight a critical role to Ni-S bonding and active site stabilization. Inorg Chem 2011; 50:10460-71. [PMID: 21932766 PMCID: PMC3561719 DOI: 10.1021/ic2016462] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nickel superoxide dismutase (Ni-SOD) catalyzes the disproportionation of the superoxide radical to O(2) and H(2)O(2) utilizing the Ni(III/II) redox couple. The Ni center in Ni-SOD resides in an unusual coordination environment that is distinct from other SODs. In the reduced state (Ni-SOD(red)), Ni(II) is ligated to a primary amine-N from His1, anionic carboxamido-N/thiolato-S from Cys2, and a second thiolato-S from Cys6 to complete a NiN(2)S(2) square-planar coordination motif. Utilizing the dipeptide N(2)S(2-) ligand, H(2)N-Gly-l-Cys-OMe (GC-OMeH(2)), an accurate model of the structural and electronic contributions provided by His1 and Cys2 in Ni-SOD(red), we constructed the dinuclear sulfur-bridged metallosynthon, [Ni(2)(GC-OMe)(2)] (1). From 1 we prepared the following monomeric Ni(II)-N(2)S(2) complexes: K[Ni(GC-OMe)(SC(6)H(4)-p-Cl)] (2), K[Ni(GC-OMe)(S(t)Bu)] (3), K[Ni(GC-OMe)(SC(6)H(4)-p-OMe)] (4), and K[Ni(GC-OMe)(SNAc)] (5). The design strategy in utilizing GC-OMe(2-) is analogous to one which we reported before (see Inorg. Chem. 2009, 48, 5620 and Inorg. Chem. 2010, 49, 7080) where Ni-SOD(red) active site mimics can be assembled at will with electronically variant RS(-) ligands. Discussed herein is our initial account pertaining to the aqueous behavior of isolable, small-molecule Ni-SOD model complexes (non-maquette based). Spectroscopic (FTIR, UV-vis, ESI-MS, XAS) and electrochemical (CV) measurements suggest that 2-5 successfully simulate many of the electronic features of Ni-SOD(red). Furthermore, the aqueous studies reveal a dynamic behavior with regard to RS(-) lability and bridging interactions, suggesting a stabilizing role brought about by the protein architecture.
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Affiliation(s)
- Eric M. Gale
- Department of Chemistry, University of Georgia, 1001 Cedar Street, Athens, Georgia 30602
| | - Darin M. Cowart
- Department of Chemistry, University of Georgia, 1001 Cedar Street, Athens, Georgia 30602
| | - Robert A. Scott
- Department of Chemistry, University of Georgia, 1001 Cedar Street, Athens, Georgia 30602
| | - Todd C. Harrop
- Department of Chemistry, University of Georgia, 1001 Cedar Street, Athens, Georgia 30602
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23
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Gale EM, Simmonett AC, Telser J, Schaefer HF, Harrop TC. Toward Functional Ni-SOD Biomimetics: Achieving a Structural/Electronic Correlation with Redox Dynamics. Inorg Chem 2011; 50:9216-8. [DOI: 10.1021/ic201822f] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Eric M. Gale
- Department of Chemistry and Center for Computational Chemistry, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
| | - Andrew C. Simmonett
- Department of Chemistry and Center for Computational Chemistry, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, 430 South Michigan Avenue, Chicago, Illinois 60605, United States
| | - Henry F. Schaefer
- Department of Chemistry and Center for Computational Chemistry, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
| | - Todd C. Harrop
- Department of Chemistry and Center for Computational Chemistry, The University of Georgia, 1001 Cedar Street, Athens, Georgia 30602, United States
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