1
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Abd Elhameed HAH, Hajdu B, Jancsó A, Kéri A, Galbács G, Hunyadi-Gulyás É, Gyurcsik B. Modulation of the catalytic activity of a metallonuclease by tagging with oligohistidine. J Inorg Biochem 2020; 206:111013. [PMID: 32088594 DOI: 10.1016/j.jinorgbio.2020.111013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/23/2020] [Accepted: 01/27/2020] [Indexed: 11/19/2022]
Abstract
Peptide tags are extensively used for affinity purification of proteins. In an optimal case, these tags can be completely removed from the purified protein by a specific protease mediated hydrolysis. However, the interactions of these tags with the target protein may also be utilized for the modulation of the protein function. Here we show that the C-terminal hexahistidine (6 × His) tag can influence the catalytic activity of the nuclease domain of the Colicin E7 metallonuclease (NColE7) used by E. coli to kill competing bacteria under stress conditions. This enzyme non-specifically cleaves the DNA that results in cytotoxicity. We have successfully cloned the genes of NColE7 protein and its R447G mutant into a modified pET-21a DNA vector fusing the affinity tag to the protein upon expression, which would be otherwise not possible in the absence of the gene of the Im7 inhibitory protein. This reflects the inhibitory effect of the 6 × His fusion tag on the nuclease activity, which proved to be a complex process via both coordinative and non-specific steric interactions. The modulatory effect of Zn2+ ion was observed in the catalytic activity experiments. The DNA cleavage ability of the 6 × His tagged enzyme was first enhanced by an increase of metal ion concentration, while high excess of Zn2+ ions caused a lower rate of the DNA cleavage. Modelling of the coordinative effect of the fusion tag by external chelators suggested ternary complex formation instead of removal of the metal ion from the active center.
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Affiliation(s)
- Heba A H Abd Elhameed
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary
| | - Bálint Hajdu
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary
| | - Attila Jancsó
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary
| | - Albert Kéri
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary
| | - Gábor Galbács
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary
| | - Éva Hunyadi-Gulyás
- Laboratory of Proteomics Research, Biological Research Centre, Temesvári krt. 62, H-6726 Szeged, Hungary
| | - Béla Gyurcsik
- Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7, H-6720 Szeged, Hungary.
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Dancs Á, Selmeczi K, May NV, Gajda T. On the copper(ii) binding of asymmetrically functionalized tripodal peptides: solution equilibrium, structure, and enzyme mimicking. NEW J CHEM 2018. [DOI: 10.1039/c7nj04716a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The increasing histidyl functionalisation of tren results in the fundamental impact on the structure, stability and catecholase activity of its copper(ii) complexes.
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Affiliation(s)
- Ágnes Dancs
- Department of Inorganic and Analytical Chemistry
- University of Szeged
- H-6720 Szeged
- Hungary
- Université de Lorraine – CNRS
| | - Katalin Selmeczi
- Université de Lorraine – CNRS
- UMR 7053 L2CM
- 54506 Vandœuvre-lès-Nancy
- France
| | - Nóra V. May
- Institute of Organic Chemistry
- Research Centre for Natural Sciences HAS
- H-1117 Budapest
- Hungary
| | - Tamás Gajda
- Department of Inorganic and Analytical Chemistry
- University of Szeged
- H-6720 Szeged
- Hungary
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3
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Kowalik-Jankowska T, Kadej A, Kuczer M, Czarniewska E. Copper(II) complexes of the Neb- colloostatin analogues containing histidine residue structure stability biological activity. Polyhedron 2017. [DOI: 10.1016/j.poly.2017.06.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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4
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Dancs Á, May NV, Selmeczi K, Darula Z, Szorcsik A, Matyuska F, Páli T, Gajda T. Tuning the coordination properties of multi-histidine peptides by using a tripodal scaffold: solution chemical study and catechol oxidase mimicking. NEW J CHEM 2017. [DOI: 10.1039/c6nj03126a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Histidine-rich tripodal peptides form unique oligonuclear complexes with copper(ii), which exhibit efficient catecholase-like activity.
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Affiliation(s)
- Ágnes Dancs
- Department of Inorganic and Analytical Chemistry
- University of Szeged
- H-6720 Szeged
- Hungary
- Université de Lorraine – CNRS
| | - Nóra V. May
- Research Centre for Natural Sciences HAS
- H-1117 Budapest
- Hungary
| | - Katalin Selmeczi
- Université de Lorraine – CNRS
- UMR 7565 SRSMC
- 54506 Vandœuvre-lès-Nancy
- France
| | - Zsuzsanna Darula
- Institute of Biochemistry
- Biological Research Centre
- Hungarian Academy of Sciences
- H-6724 Szeged
- Hungary
| | - Attila Szorcsik
- MTA-SZTE Bioinorganic Chemistry Research Group
- H-6720 Szeged
- Hungary
| | - Ferenc Matyuska
- Department of Inorganic and Analytical Chemistry
- University of Szeged
- H-6720 Szeged
- Hungary
| | - Tibor Páli
- Institute of Biophysics
- Biological Research Centre
- Hungarian Academy of Sciences
- H-6724 Szeged
- Hungary
| | - Tamás Gajda
- Department of Inorganic and Analytical Chemistry
- University of Szeged
- H-6720 Szeged
- Hungary
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5
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Matyuska F, May NV, Bényei A, Gajda T. Control of structure, stability and catechol oxidase activity of copper(ii) complexes by the denticity of tripodal platforms. NEW J CHEM 2017. [DOI: 10.1039/c7nj02013a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The speciation and catecholase-like activity of trinuclear complexes can be fine tuned by the denticity of tripodal platforms.
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Affiliation(s)
- Ferenc Matyuska
- Department of Inorganic and Analytical Chemistry
- University of Szeged
- H-6720 Szeged
- Hungary
| | - Nóra V. May
- Research Centre for Natural Sciences HAS
- H-1117 Budapest
- Hungary
| | - Attila Bényei
- Department of Pharmaceutical Chemistry
- University of Debrecen
- Debrecen H-4032
- Hungary
| | - Tamás Gajda
- Department of Inorganic and Analytical Chemistry
- University of Szeged
- H-6720 Szeged
- Hungary
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Kadej A, Kuczer M, Czarniewska E, Urbański A, Rosiński G, Kowalik-Jankowska T. High stability and biological activity of the copper(II) complexes of alloferon 1 analogues containing tryptophan. J Inorg Biochem 2016; 163:147-161. [PMID: 27453534 DOI: 10.1016/j.jinorgbio.2016.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/21/2016] [Accepted: 07/07/2016] [Indexed: 11/28/2022]
Abstract
Copper(II) complex formation processes between the alloferon 1 (Allo1) (HGVSGHGQHGVHG) analogues where the tryptophan residue is introducing in the place His residue H1W, H6W, H9W and H12W have been studied by potentiometric, UV-visible, CD and EPR spectroscopic, and MS methods. For all analogues of alloferon 1 complex speciation have been obtained for a 1:1 metal-to-ligand molar ratio and 2:1 of H1W because of precipitation at higher (2:1, 3:1 and 4:1) ratios. At physiological pH7.4 and a 1:1 metal-to-ligand molar ratio the tryptophan analogues of alloferon 1 form the CuH-1L and/or CuH-2L complexes with the 4N binding mode. The introduction of tryptophan in place of histidine residues changes the distribution diagram of the complexes formed with the change of pH and their stability constants compared to the respective substituted alanine analogues of alloferon 1. The CuH-1L, CuH-2L and CuH-3L complexes of the tryptophan analogues are more stable from 1 to 5 log units in comparison to those of the alanine analogues. This stabilization of the complexes may result from cation(Cu(II))-π and indole/imidazole ring interactions. The induction of apoptosis in vivo, in Tenebrio molitor cells by the ligands and their copper(II) complexes at pH7.4 was studied. The biological results show that copper(II) ions in vivo did not cause any apparent apoptotic features. The most active were the H12W peptide and Cu(II)-H12W complex formed at pH7.4.
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Affiliation(s)
- Agnieszka Kadej
- Faculty of Chemistry, University of Wrocław, Joliot-Curie 14, 50-383 Wrocław, Poland
| | - Mariola Kuczer
- Faculty of Chemistry, University of Wrocław, Joliot-Curie 14, 50-383 Wrocław, Poland
| | - Elżbieta Czarniewska
- Department of Animal Physiology and Development, Institute of Experimental Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Arkadiusz Urbański
- Department of Animal Physiology and Development, Institute of Experimental Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland; Department of Systematic Zoology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Grzegorz Rosiński
- Department of Animal Physiology and Development, Institute of Experimental Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
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Matusiak A, Kuczer M, Czarniewska E, Urbański A, Rosiński G, Kowalik-Jankowska T. Copper(II) complexes of terminally free alloferon peptide mutants containing two different histidyl (H1 and H6 or H9 or H12) binding sites Structure Stability and Biological Activity. J Inorg Biochem 2015; 151:44-57. [DOI: 10.1016/j.jinorgbio.2015.06.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/27/2015] [Accepted: 06/26/2015] [Indexed: 11/25/2022]
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8
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Copper(II) complexes of alloferon 1 with point mutations (H1A) and (H9A) stability structure and biological activity. J Inorg Biochem 2014; 138:99-113. [DOI: 10.1016/j.jinorgbio.2014.05.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 05/22/2014] [Accepted: 05/23/2014] [Indexed: 01/04/2023]
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9
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Csire G, Demjén J, Timári S, Várnagy K. Electrochemical and SOD activity studies of copper(II) complexes of bis(imidazol-2-yl) derivatives. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.05.053] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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10
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Zavitsanos K, Nunes AM, Malandrinos G, Hadjiliadis N. Copper effective binding with 32–62 and 94–125 peptide fragments of histone H2B. J Inorg Biochem 2011; 105:102-10. [DOI: 10.1016/j.jinorgbio.2010.09.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Revised: 09/15/2010] [Accepted: 09/16/2010] [Indexed: 11/29/2022]
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11
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Alí-Torres J, Rodríguez-Santiago L, Sodupe M. Computational calculations of pKa values of imidazole in Cu(ii) complexes of biological relevance. Phys Chem Chem Phys 2011; 13:7852-61. [DOI: 10.1039/c0cp02319a] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Sarma R, Kalita D, Baruah JB. Solvent induced reactivity of 3,5-dimethylpyrazole towards zinc (II) carboxylates. Dalton Trans 2009:7428-36. [PMID: 19727464 DOI: 10.1039/b905534g] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactions of 3,5-dimethylpyrazole with zinc(II)acetate dihydrate and varieties of aromatic carboxylic acids led to formation of mono-nuclear zinc complexes of composition [Zn(HDMP)2(RCO2)2] (R = C6H5, p-CH3-C6H4, p-NO2-C6H4 etc. HDMP = 3,5-dimethylpyrazole) in methanol, whereas the same reactants in dimethylformamide (DMF) gave binuclear 3,5-dimethylpyrazolato bridged zinc carboxylate complexes containing monodentate 3,5-dimethylpyraozole ligands with composition [Zn2(mu-DMP)2(HDMP)2(RCO2)2]. The mononuclear complexes can be converted to the corresponding binuclear complexes by simply dissolving in DMF. The reaction of zinc(II)acetate dihydrate with p-nitrobenzoic acid and 3,5-dimethylpyrazole in different solvents gave solvated mononuclear complexes of the corresponding solvent. All these solvated complexes having the core [Zn(HDMP)2(p-NO2-C6H4CO2)2] contain two structurally independent molecules in the asymmetric unit (Z' = 2).
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Affiliation(s)
- Rupam Sarma
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781 039, Assam, India
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13
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Zoroddu MA, Kowalik-Jankowska T, Medici S, Peana M, Kozlowski H. Copper(II) binding to Cap43 protein fragments. Dalton Trans 2008:6127-34. [PMID: 18985244 DOI: 10.1039/b808600a] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The C-terminal 20 and 30 amino acid sequences of Cap43 protein were chosen as models to study their interactions with Cu(II) ions. The behaviour of the 20 amino acid Ac-TRSRSH6TSEG-TRSRSH16TSEG and 30 amino acid Ac-TRSRSH6TSEG-TRSRSH16TSEG-TRSRSH26TSEG peptides towards Cu(II) ions at different pH values and different ligand-to-metal molar ratios, was examined. Spectroscopic (EPR, UV-Vis) and potentiometric techniques were performed to understand the details of metal binding to the peptides. The study showed that, starting from pH 4.0, each 10 amino acid fragment T1R2S3R4S5H6T7S8E9G10 was able to independently coordinate a single Cu(II) ion. The coordination mode involved the imidazole nitrogen of histidine H6 residue, and three amidic nitrogens from histidine H6, serine S5, and arginine R4 residues, respectively.
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14
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Burzlaff N. Tripodal N,N,O-ligands for metalloenzyme models and organometallics. ADVANCES IN INORGANIC CHEMISTRY 2008. [DOI: 10.1016/s0898-8838(08)00004-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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15
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Várnagy K, Csorba T, Kiss D, Garribba E, Micera G, Sanna D. VIVO Complexes of Bis(imidazol-2-yl) Derivatives: A Potentiometric, Spectroscopic and DFT Study. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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Osz K, Lente G, Kallay C. New protonation microequilibrium treatment in the case of some amino acid and peptide derivatives containing a bis(imidazolyl)methyl group. J Phys Chem B 2007; 109:1039-47. [PMID: 16866477 DOI: 10.1021/jp047515n] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a microequilibrium analysis of a series of amino acid and peptide derivatives containing the chelating bis(imidazol-2-yl)methyl group (BIP, Gly-BIMA, His-BIMA, alpha-Glu-BIMA, gamma-Glu-BIMA, and Phe-His-BIMA). NMR measurements were performed in D2O to follow the deprotonation steps. The software PSEQUAD and a specialized program written in MATLAB were used to determine the macroscopic and microscopic constants. The method assumes that the effect of pH on the chemical shift of an NMR-active nucleus can be interpreted by adding the independent effects of the protonation of individual sites. For derivatives containing histidine (His-BIMA and Phe-His-BIMA), the deprotonation steps of the second imidazole and the His-imidazole significantly overlap. In the Glu derivatives (alpha-Glu-BIMA and gamma-Glu-BIMA), the amino and the second imidazole pK values are separate; the deprotonation processes of the first imidazole nitrogen and the side-chain carboxyl group, however, significantly overlap. In gamma-Glu-BIMA, the deprotonation sequence is carboxylate-imidazole1-imidazole2-amino, while in the case of alpha-Glu-BIMA, it changes to imidazole1-carboxylate-imidazole2-amino, according to the microscopic pk values. The main advantage of the method is that it does not require the synthesis and NMR microequilibrium analysis of substances modeling the individual parts of the target ligand, in contrast to the methods used by others. The method presented here demands slightly more mathematical and computational power, which is readily available today.
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Affiliation(s)
- Katalin Osz
- Department of Inorganic and Analytical Chemistry, University of Debrecen, P.O. Box 21, Debrecen H-4010, Hungary.
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Kállay C, Várnagy K, Malandrinos G, Hadjiliadis N, Sanna D, Sóvágó I. Copper(II) complexes of terminally protected pentapeptides containing three histidyl residues in alternating positions, Ac-His-Xaa-His-Yaa-His-NH2. Dalton Trans 2006:4545-52. [PMID: 17016565 DOI: 10.1039/b608190h] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Copper(II) complexes of the pentapeptides Ac-HisAlaHisValHis-NH2, Ac-HisValHisAlaHis-NH2, Ac-HisProHisAlaHis-NH2, Ac-HisAlaHisProHis-NH2, Ac-HisGlyHisValHis-NH2 and Ac-HisValHisGlyHis-NH2 have been studied by potentiometric, UV-Vis, CD and EPR spectroscopic methods. It has been found that the pentapeptides are efficient ligands for the complexation with copper(II) and exhibit an outstanding versatility in the co-ordination geometry of complexes. The presence of three histidyl residues provides a high possibility for the formation of macrochelates via the exclusive binding of imidazole-N donor atoms. The macrochelation suppresses, but cannot preclude the deprotonation and metal ion co-ordination of amide functions and the species [CuH(-2)L] and [Cu2H(-4)L] predominate at physiological pH in equimolar solutions and in the presence of excess metal ions, respectively. It is also clear from the data that both C-terminal and internal histidyl residues can work as the anchoring sites for metal binding and subsequent amide deprotonation resulting in the formation of co-ordination isomers and dinuclear species in equimolar solutions and in the presence of excess metal ions, respectively. In more alkaline solutions (pH approximately 10) a third amide function can be deprotonated and co-ordinated in the species [CuH(-3)L]- with (N-,N-,N-,N(im)) co-ordination. The dinuclear species [Cu2H(-5)L]- and [Cu2H(-6)L](2-) containing hydroxide ions and/or imidazolato bridges are formed at high pH in the presence of excess of metal ions. The insertion of one proline into the sequence preceding histidyl residues hinders the deprotonation of amide functions at that site and the formation of only mononuclear complexes was observed with these peptides.
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Affiliation(s)
- Csilla Kállay
- Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4010, Debrecen, Hungary
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Abstract
Metal binding affinity and selectivity of peptides are reviewed with a special emphasis on the high structural variety of peptide complexes. The most common structural type of these complexes is built up by the deprotonation and metal ion coordination of subsequent amide groups in the form of fused five-membered chelate rings. The metal ion selectivity of this process and the role of various anchoring groups are discussed in detail. The highest metal binding affinity of peptides is connected to the presence of two anchoring groups in appropriate location (the "double anchor"): e.g. the NH2-Xaa-Xaa-His/Cys/Asp/Met-Xaa sequence. Among the side chain donor functions, the imidazole of histidyl and thiolate of cysteinyl residues are the most effective ligating groups and their involvement in metal binding results in a great variety of different macrochelate or loop structures and/or formation of various polynuclear complexes. Examples of these structural motifs and their possible applications have been thoroughly discussed.
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Affiliation(s)
- Imre Sóvágó
- Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4010, Debrecen, Hungary
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Meng R, Becker J, Lin FT, Saxena S, Weber SG. Binding of copper(II) to thyrotropin-releasing hormone (TRH) and its analogs. Inorganica Chim Acta 2005; 358:2933-2942. [PMID: 17160139 PMCID: PMC1643846 DOI: 10.1016/j.ica.2004.11.045] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Spectroscopy (UV-Vis, (1)H NMR, ESR) and electrochemistry revealed details of the structure of the Cu(II)-TRH (pyroglutamyl-histidyl-prolyl amide) complex. The (1)H NMR spectrum of TRH has been assigned. NMR spectra of TRH in the presence of Cu(II) showed that Cu(II) initially binds TRH through the imidazole. TRH analogs, pGlu-His-Pro-OH, pGlu-(1-Me)His-Pro-amide, pGlu-His-(3,4-dehydro)Pro-amide, pGlu-His-OH, pGlu-Glu-Pro-amide, and pGlu-Phe-Pro-amide provided comparison data. The stoichiometry of the major Cu(II)-TRH complex at pH 7.45 and greater is 1:1. The conditional formation constant (in pH 9.84 borate with 12.0 mM tartrate) for the formation of the complex is above 10(5) M(-1). The coordination starts from the 1-N of the histidyl imidazole, and then proceeds along the backbone involving the deprotonated pGlu-His amide and the lactam nitrogen of the pGlu residue. The fourth equatorial donor is an oxygen donor from water. Hydroxide begins to replace the water before the pH reaches 11. Minority species with stoichiometry of Cu-(TRH)(x) (x = 2-4) probably exist at pH lower than 8.0. In non-buffered aqueous solutions, TRH acts as a monodentate ligand and forms a Cu(II)-(TRH)(4) complex through imidazole nitrogens. All the His-containing analogs behave like TRH in terms of the above properties.
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Affiliation(s)
- Rong Meng
- Department of Chemistry, University of Pittsburgh, Chevron Science Center, Pittsburgh, PA 15260, USA
| | - James Becker
- Department of Chemistry, University of Pittsburgh, Chevron Science Center, Pittsburgh, PA 15260, USA
| | - Fu-Tyan Lin
- Department of Chemistry, University of Pittsburgh, Chevron Science Center, Pittsburgh, PA 15260, USA
| | - Sunil Saxena
- Department of Chemistry, University of Pittsburgh, Chevron Science Center, Pittsburgh, PA 15260, USA
| | - Stephen G. Weber
- Department of Chemistry, University of Pittsburgh, Chevron Science Center, Pittsburgh, PA 15260, USA
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Peters L, Hübner E, Burzlaff N. The new facial tripod ligand 3,3-bis(1-methylimidazol-2-yl)propionic acid and carbonyl complexes thereof containing manganese and rhenium. J Organomet Chem 2005. [DOI: 10.1016/j.jorganchem.2004.11.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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Bóka B, Myari A, Sóvágó I, Hadjiliadis N. Copper(II) and zinc(II) complexes of the peptides Ac-HisValHis-NH 2 and Ac-HisValGlyAsp-NH 2 related to the active site of the enzyme CuZnSOD. J Inorg Biochem 2004; 98:113-22. [PMID: 14659640 DOI: 10.1016/j.jinorgbio.2003.09.012] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Copper(II) and zinc(II) complexes of the peptides Ac-HisValHis-NH2 and Ac-HisValGlyAsp-NH2 related to the active site of the enzyme CuZnSOD were studied by potentiometric and spectroscopic (UV-Vis, CD and EPR) techniques. The results reveal that both ligands have effective metal binding sites, but the tripeptide is a much stronger complexing agent than the tetrapeptide. The formation of a macrochelate via the coordination of the imidazolyl residues is suggested in the copper(II)-Ac-HisValHis-NH2 system in the acidic pH range, while a 4N complex predominates at physiological pH. The interaction of Ac-HisValHis-NH2 with zinc(II) results in the formation of a precipitate indicating polynuclear complex formation. Both copper(II)-Ac-HisValHis-NH2 and copper(II)-HisValHis systems exhibit catalytic activity toward the dismutation of superoxide anion at physiological pH, but the saturated coordination sphere of the metal ions in both systems results in low reactivity as compared to the native enzyme.
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Affiliation(s)
- Beáta Bóka
- Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4010 Debrecen, Hungary
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22
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Kállay C, Cattari M, Sanna D, Várnagy K, Süli-Vargha H, Csámpai A, Sóvágó I, Micera G. Copper(ii) complexes of amino acid derivatives of the bis(imidazol-2-yl)methyl residue. NEW J CHEM 2004. [DOI: 10.1039/b316813a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Osz K, Várnagy K, Süli-Vargha H, Csámpay A, Sanna D, Micera G, Sóvágó I. Acid–base properties and copper(II) complexes of dipeptides containing histidine and additional chelating bis(imidazol-2-yl) residues. J Inorg Biochem 2004; 98:24-32. [PMID: 14659629 DOI: 10.1016/j.jinorgbio.2003.09.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Copper(II) complexes of dipeptides of histidine containing additional chelating bis(imidazol-2-yl) agent at the C-termini (PheHis-BIMA [N-phenylalanyl-histidyl-bis(imidazol-2-yl)methylamine] and HisPhe-BIMA [N-histidyl-phenylalanyl-bis(imidazol-2-yl)methylamine]) were studied by potentiometric, UV-Visible and Electron Paramagnetic Resonance (EPR) techniques. The imidazole nitrogen donor atoms of the bis(imidazol-2-yl)methyl group are described as the primary metal binding sites forming stable mono- and bis(ligand) complexes at acidic pH. The formation of a ligand-bridged dinuclear complex [Cu2L2]4+ is detected in equimolar solutions of copper(II) and HisPhe-BIMA. The coordination isomers of the dinuclear complex are described via the metal binding of the bis(imidazol-2-yl)methyl, amino-carbonyl and amino-imidazole(His) functions. In the case of the copper(II)-PheHis-BIMA system the [NH2, N-(amide), N(Im)] tridentate coordination of the ligand is favoured and results in the formation of di- and trinuclear complexes [Cu2H(-1)L]3+ and [Cu3H(-2)L2]4+ in equimolar solutions. The presence of these coordination modes shifts the formation of "tripeptide-like" ([NH2, N-, N-, N(Im)]-coordinated) [CuH(-2)L] complexes into alkaline pH range as compared to other dipeptide derivatives of bis(imidazol-2-yl) ligands. Although there are different types of imidazoles in these ligands, the deprotonation and coordination of the pyrrole-type N(1)H groups does not occur below pH 10.
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Affiliation(s)
- Katalin Osz
- Department of Inorganic and Analytical Chemistry, University of Debrecen, P.O. Box 21, H-4010 Debrecen, Hungary
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