1
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Farías JJ, Dántola ML, Thomas AH. Photosensitized Oxidation of Free and Peptide Tryptophan to N-Formylkynurenine. Chem Res Toxicol 2024. [PMID: 39105764 DOI: 10.1021/acs.chemrestox.4c00229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/07/2024]
Abstract
The oxidation of proteins and, in particular, of tryptophan (Trp) residues leads to chemical modifications that can affect the structure and function. The oxidative damage to proteins in photochemical processes is relevant in the skin and eyes and is related to a series of pathologies triggered by exposure to electromagnetic radiation. In this work, we studied the photosensitized formation of N-formylkynurenine (NFKyn) from Trp in different reaction systems. We used two substrates: free Trp and a peptide of nine amino acid residues, with Trp being the only oxidizable residue. Two different photosensitizers were employed: Rose Bengal (RB) and pterin (Ptr). The former is a typical type II photosensitizer [acts by producing singlet oxygen (1O2)]. Ptr is the parent compound of oxidized or aromatic pterins, natural photosensitizers that accumulate in human skin under certain pathological conditions and act mainly through type I mechanisms (generation of radicals). Experimental data were collected in steady photolysis, and the irradiated solutions were analyzed by chromatography (HPLC). Results indicate that the reaction of Trp with 1O2 initiates the process leading to NFKyn, but different competitive pathways take place depending on the photosensitizer and the substrate. In Ptr-photosensitization, a type I mechanism is involved in secondary reactions accelerating the formation of NFKyn when free Trp is the substrate.
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Affiliation(s)
- Jesuán J Farías
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT La Plata-CONICET, La Plata 1900, Argentina
| | - M Laura Dántola
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT La Plata-CONICET, La Plata 1900, Argentina
| | - Andrés H Thomas
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT La Plata-CONICET, La Plata 1900, Argentina
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2
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Zhou R, Zhang X. Effects of Tryptophan and Tyrosine on the Transformation of Monophenols in Chromophoric Dissolved Organic Matter Solutions: Enhance the Forward Transformation and Reduce the Reverse Transformation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:10108-10115. [PMID: 38813774 DOI: 10.1021/acs.est.4c02518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Tryptophan (Trp) and tyrosine (Tyr) are the primary precursors of protein-like components in dissolved organic matter. Phenolic compounds are ubiquitous in aquatic environments and are considered the main electron donor in chromophoric dissolved organic matter (CDOM). Our results showed that Trp and Tyr (50 μM) enhanced the transformation of six monophenols (20 μM) with varying numbers of -CH3 and -OCH3 substituent groups by a factor of 1.0-1.8. The enhancement factor increased with the ratio of Trp (Tyr) to monophenols. In four different CDOM solutions (5 mg C/L, pH 8.0), a maximum enhancement factor of 3.2-6.7 was observed at a Trp/monophenol concentration ratio of 50. Conversely, monophenols greatly inhibited the transformation of Trp or Tyr. The enhancement factor decreased as the initial pH increased from 3.0 to 10.0. Additionally, the enhancement factor was not directly proportional to the oxidation potential of monophenol. We propose that the promotion effects are generated through the direct oxidation of monophenols by Trp (Tyr) radicals as well as through the reaction between Trp (Tyr) radicals and the one-electron reductant of CDOM.
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Affiliation(s)
- Ruiya Zhou
- Department of Environmental Science, School of Resources and Environmental Science, Wuhan University, Wuhan 430079, P. R. China
| | - Xu Zhang
- Department of Environmental Science, School of Resources and Environmental Science, Wuhan University, Wuhan 430079, P. R. China
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3
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Koppenol WH, Sies H. Was hydrogen peroxide present before the arrival of oxygenic photosynthesis? The important role of iron(II) in the Archean ocean. Redox Biol 2024; 69:103012. [PMID: 38183797 PMCID: PMC10808959 DOI: 10.1016/j.redox.2023.103012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 12/18/2023] [Accepted: 12/22/2023] [Indexed: 01/08/2024] Open
Abstract
We address the chemical/biological history of H2O2 back at the times of the Archean eon (2.5-3.9 billion years ago (Gya)). During the Archean eon the pO2 was million-fold lower than the present pO2, starting to increase gradually from 2.3 until 0.6 Gya, when it reached ca. 0.2 bar. The observation that some anaerobic organisms can defend themselves against O2 has led to the view that early organisms could do the same before oxygenic photosynthesis had developed at about 3 Gya. This would require the anaerobic generation of H2O2, and here we examine the various mechanisms which were suggested in the literature for this. Given the concentration of Fe2+ at 20-200 μM in the Archean ocean, the estimated half-life of H2O2 is ca. 0.7 s. The oceanic H2O2 concentration was practically zero. We conclude that early organisms were not exposed to H2O2 before the arrival of oxygenic photosynthesis.
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Affiliation(s)
- Willem H Koppenol
- Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, Zürich, Switzerland.
| | - Helmut Sies
- Institute for Biochemistry and Molecular Biology I, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany; Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
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4
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Navarro J, Cepriá G, Camacho-Aguayo J, Martín S, González Orive A, de Marcos S, Galbán J. Towards new fluorometric methodologies based on the in-situ generation of gold nanoclusters. Talanta 2024; 266:125119. [PMID: 37657379 DOI: 10.1016/j.talanta.2023.125119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 08/16/2023] [Accepted: 08/23/2023] [Indexed: 09/03/2023]
Abstract
In this manuscript a method for the fluorometric determination of tyramine is described. It is based on the direct reaction between Au(III) and tyramine in a phosphate buffer which produces fluorescent gold nanoclusters (AuNC) (λexc = 320 nm, λem = 410 nm) with a diameter of 1.50 ± 0.06 nm. The Au(III) and buffer solutions are mixed and after 140 s, tyramine solution is added; which produces a fast and stable fluorescence signal. The formation of AuNC is demonstrated by STEM and, more importantly, this reaction could be followed by Atomic Fluorescence Microscopy (AFM). The method allows the determination of tyramine in the range from 6.0x10-7 M (limit of quantification) up to 1.2x10-4 M; with a relative standard deviation (RSD) ranges from 1.8% to 4.4% depending on the tyramine concentration. The mechanism of AuNC formation involves the Au(III) reduction via the phenol group and the complexation with the amine group. Putrescine and cadaverine do not produce interference, meanwhile histamine causes a proportional decrease in the signal which can be overcome by the standard addition method. The method was applied to the determination of tyramine in a tuna and cheese samples and the results obtained are in statistical agreement with these obtained using a validated or standard method.
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Affiliation(s)
- Jesús Navarro
- Analytical Biosensors Group (GBA), Analytical Chemistry Department, Faculty of Sciences, Instituto de Nanociencia y Materiales de Aragón (INMA), University of Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Gemma Cepriá
- Group of Analytical Spectroscopy and Sensors (GEAS), Instituto de Ciencias Ambientales (IUCA), Analytical Chemistry Department, Faculty of Sciences, University of Zaragoza, C/Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Javier Camacho-Aguayo
- Analytical Biosensors Group (GBA), Analytical Chemistry Department, Faculty of Sciences, Instituto de Nanociencia y Materiales de Aragón (INMA), University of Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Santiago Martín
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Departamento de Química Física, Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Alejandro González Orive
- Department of Chemistry, Materials and Nanotechnology Institute, University of La Laguna, Avda. Astrofísico Francisco Sánchez s/n, 38206, San Cristóbal de La Laguna, Spain
| | - Susana de Marcos
- Analytical Biosensors Group (GBA), Analytical Chemistry Department, Faculty of Sciences, Instituto de Nanociencia y Materiales de Aragón (INMA), University of Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Javier Galbán
- Analytical Biosensors Group (GBA), Analytical Chemistry Department, Faculty of Sciences, Instituto de Nanociencia y Materiales de Aragón (INMA), University of Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009, Zaragoza, Spain.
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5
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Geniman MP, Morozova OB, Lukzen NN, Grampp G, Yurkovskaya AV. Marcus Cross-Relationship Probed by Time-Resolved CIDNP. Int J Mol Sci 2023; 24:13860. [PMID: 37762162 PMCID: PMC10530771 DOI: 10.3390/ijms241813860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
The time-resolved CIDNP method can provide information about degenerate exchange reactions (DEEs) involving short-lived radicals. In the temperature range from 8 to 65 °C, the DEE reactions of the guanosine-5'-monophosphate anion GMP(-H)- with the neutral radical GMP(-H)•, of the N-acetyl tyrosine anion N-AcTyrO- with a neutral radical N-AcTyrO•, and of the tyrosine anion TyrO- with a neutral radical TyrO• were studied. In all the studied cases, the radicals were formed in the reaction of quenching triplet 2,2'-dipyridyl. The reorganization energies were obtained from Arrhenius plots. The rate constant of the reductive electron transfer reaction in the pair GMP(-H)•/TyrO- was determined at T = 25 °C. Rate constants of the GMP(-H)• radical reduction reactions with TyrO- and N-AcTyrO- anions calculated by the Marcus cross-relation differ from the experimental ones by two orders of magnitude. The rate constants of several other electron transfer reactions involving GMP(-H)-/GMP(-H)•, N-AcTyrO-/N-AcTyrO•, and TyrO-/TyrO• pairs calculated by cross-relation agree well with the experimental values. The rate of nuclear paramagnetic relaxation was found for the 3,5 and β-protons of TyrO• and N-AcTyrO•, the 8-proton of GMP(-H)•, and the 3,4-protons of DPH• at each temperature. In all cases, the dependences of the rate of nuclear paramagnetic relaxation on temperature are described by the Arrhenius dependence.
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Affiliation(s)
- Maksim P. Geniman
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (M.P.G.); (O.B.M.); (N.N.L.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Olga B. Morozova
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (M.P.G.); (O.B.M.); (N.N.L.)
| | - Nikita N. Lukzen
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (M.P.G.); (O.B.M.); (N.N.L.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Günter Grampp
- Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse, 9, A-8010 Graz, Austria;
| | - Alexandra V. Yurkovskaya
- International Tomography Center SB RAS, 630090 Novosibirsk, Russia; (M.P.G.); (O.B.M.); (N.N.L.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
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6
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Ledray AP, Dwaraknath S, Chakarawet K, Sponholtz MR, Merchen C, Van Stappen C, Rao G, Britt RD, Lu Y. Tryptophan Can Promote Oxygen Reduction to Water in a Biosynthetic Model of Heme Copper Oxidases. Biochemistry 2023; 62:388-395. [PMID: 36215733 DOI: 10.1021/acs.biochem.2c00300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Heme-copper oxidases (HCOs) utilize tyrosine (Tyr) to donate one of the four electrons required for the reduction of O2 to water in biological respiration, while tryptophan (Trp) is speculated to fulfill the same role in cyt bd oxidases. We previously engineered myoglobin into a biosynthetic model of HCOs and demonstrated the critical role that Tyr serves in the oxygen reduction reaction (ORR). To address the roles of Tyr and Trp in these oxidases, we herein report the preparation of the same biosynthetic model with the Tyr replaced by Trp and further demonstrate that Trp can also promote the ORR, albeit with lower activity. An X-ray crystal structure of the Trp variant shows a hydrogen-bonding network involving two water molecules that are organized by Trp, similar to that in the Tyr variant, which is absent in the crystal structure with the native Phe residue. Additional electron paramagnetic resonance measurements are consistent with the formation of a Trp radical species upon reacting with H2O2. We attribute the lower activity of the Trp variant to Trp's higher reduction potential relative to Tyr. Together, these findings demonstrate, for the first time, that Trp can indeed promote the ORR and provides a structural basis for the observation of varying activities. The results support a redox role for the conserved Trp in bd oxidase while suggesting that HCOs use Tyr instead of Trp to achieve higher reactivity.
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Affiliation(s)
- Aaron P Ledray
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Sudharsan Dwaraknath
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Khetpakorn Chakarawet
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Madeline R Sponholtz
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Claire Merchen
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Casey Van Stappen
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Guodong Rao
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - R David Britt
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Yi Lu
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.,Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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7
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Pastore AJ, Montoya A, Kamat M, Basso KB, Italia JS, Chatterjee A, Drosou M, Pantazis DA, Angerhofer A. Selective incorporation of 5-hydroxytryptophan blocks long range electron transfer in oxalate decarboxylase. Protein Sci 2023; 32:e4537. [PMID: 36482787 PMCID: PMC9801070 DOI: 10.1002/pro.4537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/28/2022] [Accepted: 12/03/2022] [Indexed: 12/13/2022]
Abstract
Oxalate decarboxylase from Bacillus subtilis is a binuclear Mn-dependent acid stress response enzyme that converts the mono-anion of oxalic acid into formate and carbon dioxide in a redox neutral unimolecular disproportionation reaction. A π-stacked tryptophan dimer, W96 and W274, at the interface between two monomer subunits facilitates long-range electron transfer between the two Mn ions and plays an important role in the catalytic mechanism. Substitution of W96 with the unnatural amino acid 5-hydroxytryptophan leads to a persistent EPR signal which can be traced back to the neutral radical of 5-hydroxytryptophan with its hydroxyl proton removed. 5-Hydroxytryptophan acts as a hole sink preventing the formation of Mn(III) at the N-terminal active site and strongly suppresses enzymatic activity. The lower boundary of the standard reduction potential for the active site Mn(II)/Mn(III) couple can therefore be estimated as 740 mV against the normal hydrogen electrode at pH 4, the pH of maximum catalytic efficiency. Our results support the catalytic importance of long-range electron transfer in oxalate decarboxylase while at the same time highlighting the utility of unnatural amino acid incorporation and specifically the use of 5-hydroxytryptophan as an energetic sink for hole hopping to probe electron transfer in redox proteins.
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Affiliation(s)
| | - Alvaro Montoya
- Department of ChemistryUniversity of FloridaGainesvilleFloridaUSA
| | - Manasi Kamat
- Department of ChemistryUniversity of FloridaGainesvilleFloridaUSA
| | - Kari B. Basso
- Department of ChemistryUniversity of FloridaGainesvilleFloridaUSA
| | - James S. Italia
- Department of ChemistryBoston CollegeChestnut HillMassachusettsUSA
| | | | - Maria Drosou
- Max‐Planck‐Institut für KohlenforschungMülheim an der RuhrGermany
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8
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Geeraerts Z, Stiller OR, Lukat-Rodgers GS, Rodgers KR. Roles of High-Valent Hemes and pH Dependence in Halite Decomposition Catalyzed by Chlorite Dismutase from Dechloromonas aromatica. ACS Catal 2022; 12:8641-8657. [DOI: 10.1021/acscatal.2c01428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zachary Geeraerts
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Olivia R. Stiller
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Gudrun S. Lukat-Rodgers
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Kenton R. Rodgers
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
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9
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Goett-Zink L, Kottke T. Plant Cryptochromes Illuminated: A Spectroscopic Perspective on the Mechanism. Front Chem 2021; 9:780199. [PMID: 34900940 PMCID: PMC8653763 DOI: 10.3389/fchem.2021.780199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/05/2021] [Indexed: 11/13/2022] Open
Abstract
Plant cryptochromes are central blue light receptors for the control of land plant and algal development including the circadian clock and the cell cycle. Cryptochromes share a photolyase homology region with about 500 amino acids and bind the chromophore flavin adenine dinucleotide. Characteristic for plant cryptochromes is a conserved aspartic acid close to flavin and an exceptionally long C-terminal extension. The mechanism of activation by excitation and reduction of the chromophore flavin adenine dinucleotide has been controversially discussed for many years. Various spectroscopic techniques have contributed to our understanding of plant cryptochromes by providing high time resolution, ambient conditions and even in-cell approaches. As a result, unifying and differing aspects of photoreaction and signal propagation have been revealed in comparison to members from other cryptochrome subfamilies. Here, we review the insight from spectroscopy on the flavin photoreaction in plant cryptochromes and present the current models on the signal propagation from flavin reduction to dissociation of the C-terminal extension.
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Affiliation(s)
- Lukas Goett-Zink
- Department of Chemistry, Bielefeld University, Bielefeld, Germany
| | - Tilman Kottke
- Department of Chemistry, Bielefeld University, Bielefeld, Germany.,Biophysical Chemistry and Diagnostics, Medical School OWL, Bielefeld University, Bielefeld, Germany
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10
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Dántola ML, Neyra Recky JR, Lorente C, Thomas AH. Photosensitized Dimerization of Tyrosine: The Oxygen Paradox †. Photochem Photobiol 2021; 98:687-695. [PMID: 34738644 DOI: 10.1111/php.13557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 11/01/2021] [Indexed: 01/22/2023]
Abstract
In electron-transfer initiated photosensitization processes, molecular oxygen (O2 ) is not involved in the first bimolecular event, but almost always participates in subsequent steps giving rise to oxygenated products. An exception to this general behavior is the photosensitized dimerization of tyrosine (Tyr), where O2 does not participate as a reactant in any step of the pathway yielding Tyr dimers (Tyr2 ). In the pterin (Ptr) photosensitized oxidation of Tyr, O2 does not directly participate in the formation of Tyr2 and quenches the triplet excited state of Ptr, the reactive species that initiates the process. However, O2 is necessary for the dimerization, phenomenon that we have named as the oxygen paradox. Here, we review the literature on the photosensitized formation of Tyr2 and present results of steady-state and time resolved experiments, in search of a mechanistic model to explain the contradictory role of O2 in this photochemical reaction system.
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Affiliation(s)
- M Laura Dántola
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT La Plata-CONICET, La Plata, Argentina
| | - Jael R Neyra Recky
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT La Plata-CONICET, La Plata, Argentina
| | - Carolina Lorente
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT La Plata-CONICET, La Plata, Argentina
| | - Andrés H Thomas
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT La Plata-CONICET, La Plata, Argentina
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11
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Wang N, Ferhan AR, Yoon BK, Jackman JA, Cho NJ, Majima T. Chemical design principles of next-generation antiviral surface coatings. Chem Soc Rev 2021; 50:9741-9765. [PMID: 34259262 DOI: 10.1039/d1cs00317h] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The ongoing coronavirus disease 2019 (COVID-19) pandemic has accelerated efforts to develop high-performance antiviral surface coatings while highlighting the need to build a strong mechanistic understanding of the chemical design principles that underpin antiviral surface coatings. Herein, we critically summarize the latest efforts to develop antiviral surface coatings that exhibit virus-inactivating functions through disrupting lipid envelopes or protein capsids. Particular attention is focused on how cutting-edge advances in material science are being applied to engineer antiviral surface coatings with tailored molecular-level properties to inhibit membrane-enveloped and non-enveloped viruses. Key topics covered include surfaces functionalized with organic and inorganic compounds and nanoparticles to inhibit viruses, and self-cleaning surfaces that incorporate photocatalysts and triplet photosensitizers. Application examples to stop COVID-19 are also introduced and demonstrate how the integration of chemical design principles and advanced material fabrication strategies are leading to next-generation surface coatings that can help thwart viral pandemics and other infectious disease threats.
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Affiliation(s)
- Nan Wang
- Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
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12
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Pastore AJ, Teo RD, Montoya A, Burg MJ, Twahir UT, Bruner SD, Beratan DN, Angerhofer A. Oxalate decarboxylase uses electron hole hopping for catalysis. J Biol Chem 2021; 297:100857. [PMID: 34097877 PMCID: PMC8254039 DOI: 10.1016/j.jbc.2021.100857] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/28/2021] [Accepted: 06/03/2021] [Indexed: 01/16/2023] Open
Abstract
The hexameric low-pH stress response enzyme oxalate decarboxylase catalyzes the decarboxylation of the oxalate mono-anion in the soil bacterium Bacillus subtilis. A single protein subunit contains two Mn-binding cupin domains, and catalysis depends on Mn(III) at the N-terminal site. The present study suggests a mechanistic function for the C-terminal Mn as an electron hole donor for the N-terminal Mn. The resulting spatial separation of the radical intermediates directs the chemistry toward decarboxylation of the substrate. A π-stacked tryptophan pair (W96/W274) links two neighboring protein subunits together, thus reducing the Mn-to-Mn distance from 25.9 Å (intrasubunit) to 21.5 Å (intersubunit). Here, we used theoretical analysis of electron hole-hopping paths through redox-active sites in the enzyme combined with site-directed mutagenesis and X-ray crystallography to demonstrate that this tryptophan pair supports effective electron hole hopping between the C-terminal Mn of one subunit and the N-terminal Mn of the other subunit through two short hops of ∼8.5 Å. Replacement of W96, W274, or both with phenylalanine led to a large reduction in catalytic efficiency, whereas replacement with tyrosine led to recovery of most of this activity. W96F and W96Y mutants share the wildtype tertiary structure. Two additional hole-hopping networks were identified leading from the Mn ions to the protein surface, potentially protecting the enzyme from high Mn oxidation states during turnover. Our findings strongly suggest that multistep hole-hopping transport between the two Mn ions is required for enzymatic function, adding to the growing examples of proteins that employ aromatic residues as hopping stations.
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Affiliation(s)
- Anthony J Pastore
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Ruijie D Teo
- Department of Chemistry, Duke University, Durham, North Carolina, USA
| | - Alvaro Montoya
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Matthew J Burg
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Umar T Twahir
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Steven D Bruner
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - David N Beratan
- Department of Chemistry, Duke University, Durham, North Carolina, USA.
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13
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Abstract
Click chemistry has been established rapidly as one of the most valuable methods for the chemical transformation of complex molecules. Due to the rapid rates, clean conversions to the products, and compatibility of the reagents and reaction conditions even in complex settings, it has found applications in many molecule-oriented disciplines. From the vast landscape of click reactions, approaches have emerged in the past decade centered around oxidative processes to generate in situ highly reactive synthons from dormant functionalities. These approaches have led to some of the fastest click reactions know to date. Here, we review the various methods that can be used for such oxidation-induced "one-pot" click chemistry for the transformation of small molecules, materials, and biomolecules. A comprehensive overview is provided of oxidation conditions that induce a click reaction, and oxidation conditions are orthogonal to other click reactions so that sequential "click-oxidation-click" derivatization of molecules can be performed in one pot. Our review of the relevant literature shows that this strategy is emerging as a powerful approach for the preparation of high-performance materials and the generation of complex biomolecules. As such, we expect that oxidation-induced "one-pot" click chemistry will widen in scope substantially in the forthcoming years.
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Affiliation(s)
- Bauke Albada
- Laboratory of Organic Chemistry, Wageningen University & Research, Stippeneng 4, 6807 WE Wageningen, The Netherlands
| | - Jordi F Keijzer
- Laboratory of Organic Chemistry, Wageningen University & Research, Stippeneng 4, 6807 WE Wageningen, The Netherlands
| | - Han Zuilhof
- Laboratory of Organic Chemistry, Wageningen University & Research, Stippeneng 4, 6807 WE Wageningen, The Netherlands.,School of Pharmaceutical Sciences and Technology, Tianjin University, Tianjin 300072, China.,Department of Chemical and Materials Engineering, Faculty of Engineering, King Abdulaziz University, 21589 Jeddah, Saudi Arabia
| | - Floris van Delft
- Laboratory of Organic Chemistry, Wageningen University & Research, Stippeneng 4, 6807 WE Wageningen, The Netherlands.,Synaffix BV, Industrielaan 63, 5349 AE, Oss, The Netherlands
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14
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Baptista MS, Cadet J, Greer A, Thomas AH. Photosensitization Reactions of Biomolecules: Definition, Targets and Mechanisms. Photochem Photobiol 2021; 97:1456-1483. [PMID: 34133762 DOI: 10.1111/php.13470] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/13/2021] [Indexed: 02/07/2023]
Abstract
Photosensitization reactions have been demonstrated to be largely responsible for the deleterious biological effects of UV and visible radiation, as well as for the curative actions of photomedicine. A large number of endogenous and exogenous photosensitizers, biological targets and mechanisms have been reported in the past few decades. Evolving from the original definitions of the type I and type II photosensitized oxidations, we now provide physicochemical frameworks, classifications and key examples of these mechanisms in order to organize, interpret and understand the vast information available in the literature and the new reports, which are in vigorous growth. This review surveys in an extended manner all identified photosensitization mechanisms of the major biomolecule groups such as nucleic acids, proteins, lipids bridging the gap with the subsequent biological processes. Also described are the effects of photosensitization in cells in which UVA and UVB irradiation triggers enzyme activation with the subsequent delayed generation of superoxide anion radical and nitric oxide. Definitions of photosensitized reactions are identified in biomolecules with key insights into cells and tissues.
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Affiliation(s)
| | - Jean Cadet
- Département de Médecine Nucléaire et de Radiobiologie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Alexander Greer
- Department of Chemistry, Brooklyn College, Brooklyn, NY, USA.,Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, USA
| | - Andrés H Thomas
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), CCT La Plata-CONICET, La Plata, Argentina
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15
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Oxidation of ethidium-based probes by biological radicals: mechanism, kinetics and implications for the detection of superoxide. Sci Rep 2020; 10:18626. [PMID: 33122809 PMCID: PMC7596101 DOI: 10.1038/s41598-020-75373-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 10/13/2020] [Indexed: 12/21/2022] Open
Abstract
Hydroethidine (HE) and hydropropidine (\documentclass[12pt]{minimal}
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\begin{document}$$\hbox {HPr}^{+}$$\end{document}HPr+) are fluorogenic probes used for the detection of the intra- and extracellular superoxide radical anion (\documentclass[12pt]{minimal}
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\begin{document}$$\hbox {O}_{ {2}}^{\bullet -}$$\end{document}O2∙-). In this study, we provide evidence that HE and \documentclass[12pt]{minimal}
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\begin{document}$$\hbox {HPr}^{+}$$\end{document}HPr+ react rapidly with the biologically relevant radicals, including the hydroxyl radical, peroxyl radicals, the trioxidocarbonate radical anion, nitrogen dioxide, and the glutathionyl radical, via one-electron oxidation, forming the corresponding radical cations. At physiological pH, the radical cations of the probes react rapidly with \documentclass[12pt]{minimal}
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\begin{document}$$\hbox {O}_{ {2}}^{\bullet -}$$\end{document}O2∙-, leading to the specific 2-hydroxylated cationic products. We determined the rate constants of the reaction between \documentclass[12pt]{minimal}
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\begin{document}$$\hbox {O}_{ {2}}^{\bullet -}$$\end{document}O2∙- and the radical cations of the probes. We also synthesized N-methylated analogs of \documentclass[12pt]{minimal}
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\begin{document}$$\hbox {HPr}^{+}$$\end{document}HPr+ and HE which were used in mechanistic studies. Methylation of the amine groups was not found to prevent the reaction between the radical cation of the probe and the superoxide, but it significantly increased the lifetime of the radical cation and had a substantial effect on the profiles of the oxidation products by inhibiting the formation of dimeric products. We conclude that the N-methylated analogs of HE and \documentclass[12pt]{minimal}
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\begin{document}$$\hbox {HPr}^{+}$$\end{document}HPr+ may be used as a scaffold for the design of a new generation of probes for intra- and extracellular superoxide.
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16
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Tyson KJ, Davis AN, Norris JL, Bartolotti LJ, Hvastkovs EG, Offenbacher AR. Impact of Local Electrostatics on the Redox Properties of Tryptophan Radicals in Azurin: Implications for Redox-Active Tryptophans in Proton-Coupled Electron Transfer. J Phys Chem Lett 2020; 11:2408-2413. [PMID: 32134666 DOI: 10.1021/acs.jpclett.0c00614] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Tyrosine and tryptophan play critical roles in facilitating proton-coupled electron transfer (PCET) processes essential to life. The local protein environment is anticipated to modulate the thermodynamics of amino acid radicals to achieve controlled, unidirectional PCET. Herein, square-wave voltammetry was employed to investigate the electrostatic effects on the redox properties of tryptophan in two variants of the protein azurin. Each variant contains a single redox-active tryptophan, W48 or W108, in a unique and buried protein environment. These tryptophan residues exhibit reversible square-wave voltammograms. A Pourbaix plot, representing the reduction potentials versus pH, is presented for the non-H-bonded W48, which has potentials comparable to those of tryptophan in solution. The reduction potentials of W108 are seen to be increased by more than 100 mV across the same pH range. Molecular dynamics shows that, despite its buried indole ring, the N-H of W108 hydrogen bonds with a water cluster, while W48 is completely excluded from interactions with water or polar groups. These redox properties provide insight into the role of the protein in tuning the reactivity of tryptophan radicals, a requirement for controlled biological PCET.
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Affiliation(s)
- Kristin J Tyson
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Amanda N Davis
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Jessica L Norris
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Libero J Bartolotti
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Eli G Hvastkovs
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Adam R Offenbacher
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
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17
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Koppenol WH, Hider RH. Iron and redox cycling. Do's and don'ts. Free Radic Biol Med 2019; 133:3-10. [PMID: 30236787 DOI: 10.1016/j.freeradbiomed.2018.09.022] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/01/2018] [Accepted: 09/14/2018] [Indexed: 12/23/2022]
Abstract
A major form of toxicity arises from the ability of iron to redox cycle, that is, to accept an electron from a reducing compound and to pass it on to H2O2 (the Fenton reaction). In order to do so, iron must be suitably complexed to avoid formation of Fe2O3. The ligands determine the electrode potential; this information should be known before experiments are carried out. Only one-electron transfer reactions are likely to be significant; thus two-electron potentials should not be used to determine whether an iron(III) complex can be reduced or oxidized. Ascorbate is the relevant reducing agent in blood serum, which means that iron toxicity in this compartment arises from the ascorbate-driven Fenton reaction. In the cytosol, an iron(II)-glutathione complex is likely to be the low-molecular weight iron complex involved in toxicity. When physiologically relevant concentrations are used the window of redox opportunity ranges from +0.1 V to +0.9 V. The electrode potential for non-transferrin-bound iron in the form of iron citrate is close to 0 V and the reduction of iron(III) citrate by ascorbate is slow. The clinically utilised chelators desferrioxamine, deferiprone and deferasirox in each case render iron complexes with large negative electrode potentials, thus being effective in preventing iron redox cycling and the associated toxicity resulting from such activity. There is still uncertainty about the product of the Fenton reaction, HO• or FeO2+.
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Affiliation(s)
- W H Koppenol
- Schwändibergstrasse 25, CH-8784 Braunwald, Switzerland; Emeritus, Department of Chemistry and Applied Biosciences, ETHZ, CH-8093 Zürich, Switzerland.
| | - R H Hider
- Department of Pharmacy, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
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18
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Affiliation(s)
- Kazuo Kobayashi
- The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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19
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Ferrer-Sueta G, Campolo N, Trujillo M, Bartesaghi S, Carballal S, Romero N, Alvarez B, Radi R. Biochemistry of Peroxynitrite and Protein Tyrosine Nitration. Chem Rev 2018; 118:1338-1408. [DOI: 10.1021/acs.chemrev.7b00568] [Citation(s) in RCA: 292] [Impact Index Per Article: 48.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Gerardo Ferrer-Sueta
- Laboratorio
de Fisicoquímica Biológica, Facultad de
Ciencias, ‡Center for Free Radical and Biomedical Research, §Departamento de Bioquímica,
Facultad de Medicina, ∥Laboratorio de Enzimología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Nicolás Campolo
- Laboratorio
de Fisicoquímica Biológica, Facultad de
Ciencias, ‡Center for Free Radical and Biomedical Research, §Departamento de Bioquímica,
Facultad de Medicina, ∥Laboratorio de Enzimología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Madia Trujillo
- Laboratorio
de Fisicoquímica Biológica, Facultad de
Ciencias, ‡Center for Free Radical and Biomedical Research, §Departamento de Bioquímica,
Facultad de Medicina, ∥Laboratorio de Enzimología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Silvina Bartesaghi
- Laboratorio
de Fisicoquímica Biológica, Facultad de
Ciencias, ‡Center for Free Radical and Biomedical Research, §Departamento de Bioquímica,
Facultad de Medicina, ∥Laboratorio de Enzimología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Sebastián Carballal
- Laboratorio
de Fisicoquímica Biológica, Facultad de
Ciencias, ‡Center for Free Radical and Biomedical Research, §Departamento de Bioquímica,
Facultad de Medicina, ∥Laboratorio de Enzimología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Natalia Romero
- Laboratorio
de Fisicoquímica Biológica, Facultad de
Ciencias, ‡Center for Free Radical and Biomedical Research, §Departamento de Bioquímica,
Facultad de Medicina, ∥Laboratorio de Enzimología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Beatriz Alvarez
- Laboratorio
de Fisicoquímica Biológica, Facultad de
Ciencias, ‡Center for Free Radical and Biomedical Research, §Departamento de Bioquímica,
Facultad de Medicina, ∥Laboratorio de Enzimología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Rafael Radi
- Laboratorio
de Fisicoquímica Biológica, Facultad de
Ciencias, ‡Center for Free Radical and Biomedical Research, §Departamento de Bioquímica,
Facultad de Medicina, ∥Laboratorio de Enzimología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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20
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Erdogan H, Vandemeulebroucke A, Nauser T, Bounds PL, Koppenol WH. Jumpstarting the cytochrome P450 catalytic cycle with a hydrated electron. J Biol Chem 2017; 292:21481-21489. [PMID: 29109145 DOI: 10.1074/jbc.m117.813683] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/25/2017] [Indexed: 01/08/2023] Open
Abstract
Cytochrome P450cam (CYP101Fe3+) regioselectively hydroxylates camphor. Possible hydroxylating intermediates in the catalytic cycle of this well-characterized enzyme have been proposed on the basis of experiments carried out at very low temperatures and shunt reactions, but their presence has not yet been validated at temperatures above 0 °C during a normal catalytic cycle. Here, we demonstrate that it is possible to mimic the natural catalytic cycle of CYP101Fe3+ by using pulse radiolysis to rapidly supply the second electron of the catalytic cycle to camphor-bound CYP101[FeO2]2+ Judging by the appearance of an absorbance maximum at 440 nm, we conclude that CYP101[FeOOH]2+ (compound 0) accumulates within 5 μs and decays rapidly to CYP101Fe3+, with a k440 nm of 9.6 × 104 s-1 All processes are complete within 40 μs at 4 °C. Importantly, no transient absorbance bands could be assigned to CYP101[FeO2+por•+] (compound 1) or CYP101[FeO2+] (compound 2). However, indirect evidence for the involvement of compound 1 was obtained from the kinetics of formation and decay of a tyrosyl radical. 5-Hydroxycamphor was formed quantitatively, and the catalytic activity of the enzyme was not impaired by exposure to radiation during the pulse radiolysis experiment. The rapid decay of compound 0 enabled calculation of the limits for the Gibbs activation energies for the conversions of compound 0 → compound 1 → compound 2 → CYP101Fe3+, yielding a ΔG‡ of 45, 39, and 39 kJ/mol, respectively. At 37 °C, the steps from compound 0 to the iron(III) state would take only 4 μs. Our kinetics studies at 4 °C complement the canonical mechanism by adding the dimension of time.
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Affiliation(s)
| | - An Vandemeulebroucke
- Organic Chemistry, Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, CH-8093 Zurich, Switzerland
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21
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Koppenol WH, Bounds PL. Signaling by sulfur-containing molecules. Quantitative aspects. Arch Biochem Biophys 2017; 617:3-8. [DOI: 10.1016/j.abb.2016.09.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 09/21/2016] [Accepted: 09/22/2016] [Indexed: 12/16/2022]
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22
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Ravichandran KR, Zong AB, Taguchi AT, Nocera DG, Stubbe J, Tommos C. Formal Reduction Potentials of Difluorotyrosine and Trifluorotyrosine Protein Residues: Defining the Thermodynamics of Multistep Radical Transfer. J Am Chem Soc 2017; 139:2994-3004. [PMID: 28171730 DOI: 10.1021/jacs.6b11011] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Redox-active tyrosines (Ys) play essential roles in enzymes involved in primary metabolism including energy transduction and deoxynucleotide production catalyzed by ribonucleotide reductases (RNRs). Thermodynamic characterization of Ys in solution and in proteins remains a challenge due to the high reduction potentials involved and the reactive nature of the radical state. The structurally characterized α3Y model protein has allowed the first determination of formal reduction potentials (E°') for a Y residing within a protein (Berry, B. W.; Martı́nez-Rivera, M. C.; Tommos, C. Proc. Natl. Acad. Sci. U. S. A. 2012, 109, 9739-9743). Using Schultz's technology, a series of fluorotyrosines (FnY, n = 2 or 3) was site-specifically incorporated into α3Y. The global protein properties of the resulting α3(3,5)F2Y, α3(2,3,5)F3Y, α3(2,3)F2Y and α3(2,3,6)F3Y variants are essentially identical to those of α3Y. A protein film square-wave voltammetry approach was developed to successfully obtain reversible voltammograms and E°'s of the very high-potential α3FnY proteins. E°'(pH 5.5; α3FnY(O•/OH)) spans a range of 1040 ± 3 mV to 1200 ± 3 mV versus the normal hydrogen electrode. This is comparable to the potentials of the most oxidizing redox cofactors in nature. The FnY analogues, and the ability to site-specifically incorporate them into any protein of interest, provide new tools for mechanistic studies on redox-active Ys in proteins and on functional and aberrant hole-transfer reactions in metallo-enzymes. The former application is illustrated here by using the determined α3FnY ΔE°'s to model the thermodynamics of radical-transfer reactions in FnY-RNRs and to experimentally test and support the key prediction made.
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Affiliation(s)
| | - Allan B Zong
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine , Philadelphia, Pennsylvania 19104, United States
| | | | - Daniel G Nocera
- Department of Chemistry and Chemical Biology, Harvard University , 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | | | - Cecilia Tommos
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine , Philadelphia, Pennsylvania 19104, United States
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23
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Izquierdo MA, Wadhavane PD, Vigara L, Burguete MI, Galindo F, Luis SV. The interaction of amino acids with macrocyclic pH probes of pseudopeptidic nature. Photochem Photobiol Sci 2017; 16:1320-1326. [DOI: 10.1039/c7pp00167c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The fluorescence quenching, by a series of amino acids, of pseudopeptidic compounds acting as probes for cellular acidity has been investigated.
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Affiliation(s)
- M. Angeles Izquierdo
- Universitat Jaume I
- Departamento de Química Inorgánica y Orgánica
- E-12071 Castellón
- Spain
| | - Prashant D. Wadhavane
- Universitat Jaume I
- Departamento de Química Inorgánica y Orgánica
- E-12071 Castellón
- Spain
| | - Laura Vigara
- Universitat Jaume I
- Departamento de Química Inorgánica y Orgánica
- E-12071 Castellón
- Spain
| | - M. Isabel Burguete
- Universitat Jaume I
- Departamento de Química Inorgánica y Orgánica
- E-12071 Castellón
- Spain
| | - Francisco Galindo
- Universitat Jaume I
- Departamento de Química Inorgánica y Orgánica
- E-12071 Castellón
- Spain
| | - Santiago V. Luis
- Universitat Jaume I
- Departamento de Química Inorgánica y Orgánica
- E-12071 Castellón
- Spain
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