1
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Burgener S, Dačević B, Zhang X, Ward TR. Binding Interactions and Inhibition Mechanisms of Gold Complexes in Thiamine Diphosphate-Dependent Enzymes. Biochemistry 2023; 62:3303-3311. [PMID: 37931174 DOI: 10.1021/acs.biochem.3c00376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Thiamine diphosphate (ThDP)-dependent enzymes possess the unique ability to generate a carbene within their active site. In this study, we sought to harness this carbene to produce a Au(I) N-heterocyclic complex directly in the active site of ThDP enzymes, thereby establishing a novel platform for artificial metalloenzymes. Because direct metalation of ThDP proved challenging, we synthesized a ThDP mimic that acts as a competitive inhibitor with a high affinity (Ki = 1.5 μM). Upon metalation with Au(I), we observed that the complex became a more potent inhibitor (Ki = 0.7 μM). However, detailed analysis of the inhibition mode, native mass spectrometry, and size exclusion experiments revealed that the complex does not bind specifically to the active site of ThDP enzymes. Instead, it exhibits unspecific binding and exceeds the 1:1 stoichiometry. Similar binding patterns were observed for other Au(I) species. These findings prompt an important question regarding the inherent propensity of ThDP enzymes to bind strongly to Au. If this phenomenon holds true, it could pave the way for the development of Au-based drugs targeting these enzymes.
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Affiliation(s)
- Simon Burgener
- Department of Chemistry, University of Basel, Mattenstrasse 24a, BPR 1096 4058, Basel, Switzerland
| | - Bratislav Dačević
- Department of Chemistry, University of Basel, Mattenstrasse 24a, BPR 1096 4058, Basel, Switzerland
| | - Xiang Zhang
- Department of Chemistry, University of Basel, Mattenstrasse 24a, BPR 1096 4058, Basel, Switzerland
| | - Thomas R Ward
- Department of Chemistry, University of Basel, Mattenstrasse 24a, BPR 1096 4058, Basel, Switzerland
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2
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Galassi R, Luciani L, Wang J, Vincenzetti S, Cui L, Amici A, Pucciarelli S, Marchini C. Breast Cancer Treatment: The Case of Gold(I)-Based Compounds as a Promising Class of Bioactive Molecules. Biomolecules 2022; 12:biom12010080. [PMID: 35053228 PMCID: PMC8774004 DOI: 10.3390/biom12010080] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 12/23/2021] [Accepted: 12/30/2021] [Indexed: 02/01/2023] Open
Abstract
Breast cancers (BCs) may present dramatic diagnoses, both for ineffective therapies and for the limited outcomes in terms of lifespan. For these types of tumors, the search for new drugs is a primary necessity. It is widely recognized that gold compounds are highly active and extremely potent as anticancer agents against many cancer cell lines. The presence of the metal plays an essential role in the activation of the cytotoxicity of these coordination compounds, whose activity, if restricted to the ligands alone, would be non-existent. On the other hand, gold exhibits a complex biochemistry, substantially variable depending on the chemical environments around the central metal. In this review, the scientific findings of the last 6–7 years on two classes of gold(I) compounds, containing phosphane or carbene ligands, are reviewed. In addition to this class of Au(I) compounds, the recent developments in the application of Auranofin in regards to BCs are reported. Auranofin is a triethylphosphine-thiosugar compound that, being a drug approved by the FDA—therefore extensively studied—is an interesting lead gold compound and a good comparison to understand the activities of structurally related Au(I) compounds.
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Affiliation(s)
- Rossana Galassi
- Chemistry Division, School of Science and Technology, University of Camerino, 62032 Camerino, Italy;
- Correspondence: (R.G.); (C.M.)
| | - Lorenzo Luciani
- Chemistry Division, School of Science and Technology, University of Camerino, 62032 Camerino, Italy;
| | - Junbiao Wang
- School of Biosciences and Veterinary Medicine, University of Camerino, 62032 Camerino, Italy; (J.W.); (S.V.); (L.C.); (A.A.); (S.P.)
| | - Silvia Vincenzetti
- School of Biosciences and Veterinary Medicine, University of Camerino, 62032 Camerino, Italy; (J.W.); (S.V.); (L.C.); (A.A.); (S.P.)
| | - Lishan Cui
- School of Biosciences and Veterinary Medicine, University of Camerino, 62032 Camerino, Italy; (J.W.); (S.V.); (L.C.); (A.A.); (S.P.)
| | - Augusto Amici
- School of Biosciences and Veterinary Medicine, University of Camerino, 62032 Camerino, Italy; (J.W.); (S.V.); (L.C.); (A.A.); (S.P.)
| | - Stefania Pucciarelli
- School of Biosciences and Veterinary Medicine, University of Camerino, 62032 Camerino, Italy; (J.W.); (S.V.); (L.C.); (A.A.); (S.P.)
| | - Cristina Marchini
- School of Biosciences and Veterinary Medicine, University of Camerino, 62032 Camerino, Italy; (J.W.); (S.V.); (L.C.); (A.A.); (S.P.)
- Correspondence: (R.G.); (C.M.)
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3
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Tolbatov I, Marrone A, Coletti C, Re N. Computational Studies of Au(I) and Au(III) Anticancer MetalLodrugs: A Survey. Molecules 2021; 26:7600. [PMID: 34946684 PMCID: PMC8707411 DOI: 10.3390/molecules26247600] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/29/2021] [Accepted: 12/12/2021] [Indexed: 11/16/2022] Open
Abstract
Owing to the growing hardware capabilities and the enhancing efficacy of computational methodologies, computational chemistry approaches have constantly become more important in the development of novel anticancer metallodrugs. Besides traditional Pt-based drugs, inorganic and organometallic complexes of other transition metals are showing increasing potential in the treatment of cancer. Among them, Au(I)- and Au(III)-based compounds are promising candidates due to the strong affinity of Au(I) cations to cysteine and selenocysteine side chains of the protein residues and to Au(III) complexes being more labile and prone to the reduction to either Au(I) or Au(0) in the physiological milieu. A correct prediction of metal complexes' properties and of their bonding interactions with potential ligands requires QM computations, usually at the ab initio or DFT level. However, MM, MD, and docking approaches can also give useful information on their binding site on large biomolecular targets, such as proteins or DNA, provided a careful parametrization of the metal force field is employed. In this review, we provide an overview of the recent computational studies of Au(I) and Au(III) antitumor compounds and of their interactions with biomolecular targets, such as sulfur- and selenium-containing enzymes, like glutathione reductases, glutathione peroxidase, glutathione-S-transferase, cysteine protease, thioredoxin reductase and poly (ADP-ribose) polymerase 1.
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Affiliation(s)
- Iogann Tolbatov
- Institut de Chimie Moleculaire de l’Université de Bourgogne (ICMUB), Université de Bourgogne Franche-Comté (UBFC), Avenue Alain Savary 9, 21078 Dijon, France;
| | - Alessandro Marrone
- Dipartimento di Farmacia, Università degli Studi “G. D’Annunzio” Chieti-Pescara, Via dei Vestini, 66100 Chieti, Italy; (A.M.); (C.C.)
| | - Cecilia Coletti
- Dipartimento di Farmacia, Università degli Studi “G. D’Annunzio” Chieti-Pescara, Via dei Vestini, 66100 Chieti, Italy; (A.M.); (C.C.)
| | - Nazzareno Re
- Dipartimento di Farmacia, Università degli Studi “G. D’Annunzio” Chieti-Pescara, Via dei Vestini, 66100 Chieti, Italy; (A.M.); (C.C.)
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4
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Abstract
The regium-π interaction is an attractive noncovalent force between group 11 elements (Cu, Ag, and Au) acting as Lewis acids and aromatic surfaces. Herein, we report for the first time experimental (Protein Data Bank analysis) and theoretical (RI-MP2/def2-TZVP level of theory) evidence of regium-π bonds involving Au(I) and aromatic amino acids (Phe, Tyr, Trp, and His). These findings might be important in the field of drug design and for retrospectively understanding the role of gold in proteins.
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Affiliation(s)
- María de Las Nieves Piña
- Department of Chemistry, Universitat de les Illes Balears, Crta. de Valldemossa km 7.5, 07122 Palma (Baleares), Spain
| | - Antonio Frontera
- Department of Chemistry, Universitat de les Illes Balears, Crta. de Valldemossa km 7.5, 07122 Palma (Baleares), Spain
| | - Antonio Bauzá
- Department of Chemistry, Universitat de les Illes Balears, Crta. de Valldemossa km 7.5, 07122 Palma (Baleares), Spain
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5
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6
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Tolbatov I, Coletti C, Marrone A, Re N. Reactivity of Gold(I) Monocarbene Complexes with Protein Targets: A Theoretical Study. Int J Mol Sci 2019; 20:ijms20040820. [PMID: 30769823 PMCID: PMC6412330 DOI: 10.3390/ijms20040820] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/06/2019] [Accepted: 02/12/2019] [Indexed: 01/02/2023] Open
Abstract
Neutral N–heterocyclic carbene gold(I) compounds such as IMeAuCl are widely used both in homogeneous catalysis and, more recently, in medicinal chemistry as promising antitumor agents. In order to shed light on their reactivity with protein side chains, we have carried out density functional theory (DFT) calculations on the thermodynamics and kinetics of their reactions with water and various nucleophiles as a model of plausible protein binding sites such as arginine, aspartic acid, asparagine, cysteine, glutamic acid, glutamine, histidine, lysine, methionine, selenocysteine, and the N-terminal group. In agreement with recent experimental data, our results suggest that IMeAuCl easily interacts with all considered biological targets before being hydrated—unless sterically prevented—and allows the establishment of an order of thermodynamic stability and of kinetic reactivity for its binding to protein residues.
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Affiliation(s)
- Iogann Tolbatov
- Dipartimento di Farmacia, Università degli Studi "G. D'Annunzio" Chieti-Pescara, Via dei Vestini, I-66100 Chieti, Italy.
| | - Cecilia Coletti
- Dipartimento di Farmacia, Università degli Studi "G. D'Annunzio" Chieti-Pescara, Via dei Vestini, I-66100 Chieti, Italy.
| | - Alessandro Marrone
- Dipartimento di Farmacia, Università degli Studi "G. D'Annunzio" Chieti-Pescara, Via dei Vestini, I-66100 Chieti, Italy.
| | - Nazzareno Re
- Dipartimento di Farmacia, Università degli Studi "G. D'Annunzio" Chieti-Pescara, Via dei Vestini, I-66100 Chieti, Italy.
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7
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Ferraro G, Giorgio A, Mansour AM, Merlino A. Protein-mediated disproportionation of Au(i): insights from the structures of adducts of Au(iii) compounds bearingN,N-pyridylbenzimidazole derivatives with lysozyme. Dalton Trans 2019; 48:14027-14035. [DOI: 10.1039/c9dt02729g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Structural data of protein/gold adducts suggest protein-mediated reduction of Au(iii) into Au(i) and disproportionation of Au(i) into Au(iii) and Au(0).
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Affiliation(s)
- Giarita Ferraro
- Department of Chemistry “Ugo Schiff”
- University of Florence
- Sesto Fiorentino
- Italy
| | - Anna Giorgio
- Department of Chemical Sciences
- University of Naples Federico II
- Complesso Universitario di Monte Sant'Angelo
- Naples
- Italy
| | | | - Antonello Merlino
- Department of Chemical Sciences
- University of Naples Federico II
- Complesso Universitario di Monte Sant'Angelo
- Naples
- Italy
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8
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Russo Krauss I, Ferraro G, Pica A, Márquez JA, Helliwell JR, Merlino A. Principles and methods used to grow and optimize crystals of protein-metallodrug adducts, to determine metal binding sites and to assign metal ligands. Metallomics 2018; 9:1534-1547. [PMID: 28967006 DOI: 10.1039/c7mt00219j] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The characterization of the interactions between biological macromolecules (proteins and nucleic acids) and metal-based drugs is a fundamental prerequisite for understanding their mechanisms of action. X-ray crystallography enables the structural analysis of such complexes with atomic level detail. However, this approach requires the preparation of highly diffracting single crystals, the measurement of diffraction patterns and the structural analysis and interpretation of macromolecule-metal interactions from electron density maps. In this review, we describe principles and methods used to grow and optimize crystals of protein-metallodrug adducts, to determine metal binding sites and to assign and validate metal ligands. Examples from the literature and experience in our own laboratory are provided and key challenges are described, notably crystallization and molecular model refinement against the X-ray diffraction data.
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Affiliation(s)
- Irene Russo Krauss
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cintia, I-80126, Napoli, Italy.
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9
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Messori L, Merlino A. Protein metalation by metal-based drugs: X-ray crystallography and mass spectrometry studies. Chem Commun (Camb) 2018; 53:11622-11633. [PMID: 29019481 DOI: 10.1039/c7cc06442j] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The combined use of X-ray crystallography and mass spectrometry represents a valuable strategy to investigate and characterize protein metalation induced by anticancer metal-based drugs. Here, we summarize a series of significant results recently obtained in our laboratories upon the examination of the structures of several adducts of proteins with representative metallodrugs (mostly containing ruthenium, gold and platinum). The general mechanisms of protein metalation that emerge from a careful comparative analysis of these structures are illustrated and their mechanistic implications are discussed. Possible directions for future work in the field are delineated.
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Affiliation(s)
- L Messori
- Department of Chemistry, University of Florence, Italy.
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10
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Ferraro G, Monti DM, Amoresano A, Pontillo N, Petruk G, Pane F, Cinellu MA, Merlino A. Gold-based drug encapsulation within a ferritin nanocage: X-ray structure and biological evaluation as a potential anticancer agent of the Auoxo3-loaded protein. Chem Commun (Camb) 2018; 52:9518-21. [PMID: 27326513 DOI: 10.1039/c6cc02516a] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Auoxo3, a cytotoxic gold(iii) compound, was encapsulated within a ferritin nanocage. Inductively coupled plasma mass spectrometry, circular dichroism, UV-Vis absorption spectroscopy and X-ray crystallography confirm the potential-drug encapsulation. The structure shows that naked Au(i) ions bind to the side chains of Cys48, His49, His114, His114 and Cys126, Cys126, His132, His147. The gold-encapsulated nanocarrier has a cytotoxic effect on different aggressive human cancer cells, whereas it is significantly less cytotoxic for non-tumorigenic cells.
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Affiliation(s)
- Giarita Ferraro
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cintia, I-80126, Napoli, Italy.
| | - Daria Maria Monti
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cintia, I-80126, Napoli, Italy.
| | - Angela Amoresano
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cintia, I-80126, Napoli, Italy.
| | - Nicola Pontillo
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cintia, I-80126, Napoli, Italy.
| | - Ganna Petruk
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cintia, I-80126, Napoli, Italy.
| | - Francesca Pane
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cintia, I-80126, Napoli, Italy.
| | - Maria Agostina Cinellu
- Department of Chemistry and Pharmacy, University of Sassari, Via Vienna 2, 07100 Sassari, Italy and CIRCC, Consorzio Interuniversitario Reattività Chimica e Catalisi, Università di Bari, Via Celso Ulpiani 27, 70126 Bari, Italy
| | - Antonello Merlino
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cintia, I-80126, Napoli, Italy. and CNR Institute of Biostructures and Bioimages, Via Mezzocannone 16, I-80126, Napoli, Italy
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11
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Marzo T, Cirri D, Gabbiani C, Gamberi T, Magherini F, Pratesi A, Guerri A, Biver T, Binacchi F, Stefanini M, Arcangeli A, Messori L. Auranofin, Et 3PAuCl, and Et 3PAuI Are Highly Cytotoxic on Colorectal Cancer Cells: A Chemical and Biological Study. ACS Med Chem Lett 2017; 8:997-1001. [PMID: 29057040 DOI: 10.1021/acsmedchemlett.7b00162] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 09/06/2017] [Indexed: 12/23/2022] Open
Abstract
The solution behavior of auranofin, Et3PAuCl and Et3PAuI, as well as their interactions with hen egg white lysozyme, single strand oligonucleotide, and ds-DNA were comparatively analyzed through NMR spectroscopy, ESI-MS, ethidium bromide displacement, DNA melting and viscometric tests. The cytotoxic effects toward representative colorectal cancer cell lines were found to be strong and similar in the three cases and a good correlation could be established between the cytotoxicity and the ability to inhibit thioredoxin reductase; remarkably, in vivo acute toxicity experiments for Et3PAuI confirmed that, similarly to auranofin, this drug is well tolerated in a murine model. Overall, a very similar profile emerges for Et3PAuI and Et3PAuCl, which retain the potent cytotoxic effects of auranofin while showing some peculiar features. These results demonstrate that the presence of the thiosugar moiety is not mandatory for the pharmacological action, suggesting that the tuning of some relevant chemical properties such as lipophilicity could be exploited to improve bioavailability, with no loss of the pharmacological effects.
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Affiliation(s)
- Tiziano Marzo
- Department
of Chemistry and Industrial Chemistry (DCCI), University of Pisa, Via Moruzzi, 13, 56124 Pisa, Italy
- Laboratory
of Metals in Medicine (MetMed), Department of Chemistry “U.
Schiff”, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - Damiano Cirri
- Laboratory
of Metals in Medicine (MetMed), Department of Chemistry “U.
Schiff”, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - Chiara Gabbiani
- Department
of Chemistry and Industrial Chemistry (DCCI), University of Pisa, Via Moruzzi, 13, 56124 Pisa, Italy
| | - Tania Gamberi
- Department
of Biochemical, Experimental and Clinical Sciences “Mario Serio”, University of Florence, Viale GB Morgagni 50, 50134 Firenze, Italy
| | - Francesca Magherini
- Department
of Biochemical, Experimental and Clinical Sciences “Mario Serio”, University of Florence, Viale GB Morgagni 50, 50134 Firenze, Italy
| | - Alessandro Pratesi
- Laboratory
of Metals in Medicine (MetMed), Department of Chemistry “U.
Schiff”, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - Annalisa Guerri
- Laboratory
of Metals in Medicine (MetMed), Department of Chemistry “U.
Schiff”, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
| | - Tarita Biver
- Department
of Chemistry and Industrial Chemistry (DCCI), University of Pisa, Via Moruzzi, 13, 56124 Pisa, Italy
| | - Francesca Binacchi
- Department
of Chemistry and Industrial Chemistry (DCCI), University of Pisa, Via Moruzzi, 13, 56124 Pisa, Italy
| | - Matteo Stefanini
- DI.V.A.L Toscana S.R.L., Via Madonna
del Piano, 6, 50019 Sesto Fiorentino, Italy
| | - Annarosa Arcangeli
- Department
of Experimental and Clinical Medicine, University of Florence, Viale GB
Morgagni 50, 50134 Firenze, Italy
| | - Luigi Messori
- Laboratory
of Metals in Medicine (MetMed), Department of Chemistry “U.
Schiff”, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
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12
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Merlino A, Marzo T, Messori L. Protein Metalation by Anticancer Metallodrugs: A Joint ESI MS and XRD Investigative Strategy. Chemistry 2017; 23:6942-6947. [DOI: 10.1002/chem.201605801] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Antonello Merlino
- Department of Chemical Sciences; University of Naples Federico II; Via Cintia 80126 Napoli Italy) and CNR Institute of Biostructure and Bioimages, Via Mezzocannone 16, 80100, Napoli (Italy
| | - Tiziano Marzo
- Department of Chemistry and Industrial Chemistry; University of Pisa; via Moruzzi, 13 56124 Pisa Italy
- Department of Chemistry; University of Florence; Via della Lastruccia 3 50019 Sesto fiorentino (FI) Italy
| | - Luigi Messori
- Department of Chemistry; University of Florence; Via della Lastruccia 3 50019 Sesto fiorentino (FI) Italy
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13
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Interactions between proteins and Ru compounds of medicinal interest: A structural perspective. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2016.08.001] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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14
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Ferraro G, Gabbiani C, Merlino A. First Crystal Structure for a Gold Carbene-Protein Adduct. Bioconjug Chem 2016; 27:1584-7. [PMID: 27364343 DOI: 10.1021/acs.bioconjchem.6b00298] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The X-ray structure of the adduct formed in the reaction between the gold N-heterocyclic carbene compound Au(NHC)Cl (with NHC = 1-butyl-3-methyl-imidazole-2-ylidene) and the model protein thaumatin is reported here. The structure reveals binding of Au(NHC)(+) fragments to distinct protein sites. Notably, binding of the gold compound occurs at lysine side chains and at the N-terminal tail; the metal binds the protein after releasing Cl(-) ligand, but retaining NHC fragment.
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Affiliation(s)
- Giarita Ferraro
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo , Via Cintia, I-80126 Napoli, Italy
| | - Chiara Gabbiani
- Department of Chemistry and Industrial Chemistry, University of Pisa , Via Moruzzi 13, 56124 Pisa, Italy
| | - Antonello Merlino
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo , Via Cintia, I-80126 Napoli, Italy
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