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Jóźwiak M, Trzmielak MA, Wasiak M. Effect of the Temperature on the Process of Preferential Solvation of 1,4-Dioxane, 12-Crown-4, 15-Crown-5 and 18-Crown-6 Ethers in the Mixture of N-Methylformamide with Water: Composition of the Solvation Shell of the Cyclic Ethers. Int J Mol Sci 2023; 24:ijms24108934. [PMID: 37240291 DOI: 10.3390/ijms24108934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/16/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
The aim of the work was to analyze the preferential solvation process, and determine the composition of the solvation shell of cyclic ethers using the calorimetric method. The heat of solution of 1,4-dioxane, 12-crown-4, 15-crown-5 and 18-crown-6 ethers in the mixture of N-methylformamide with water was measured at four temperatures, 293.15 K, 298.15 K, 303.15 K, and 308.15 K, and the standard partial molar heat capacity of cyclic ethers has been discussed. 18-crown-6 (18C6) molecules can form complexes with NMF molecules through the hydrogen bonds between -CH3 group of NMF and the oxygen atoms of 18C6. Using the model of preferential solvation, the cyclic ethers were observed to be preferentially solvated by NMF molecules. It has been proved that the molar fraction of NMF in the solvation shell of cyclic ethers is higher than that in the mixed solvent. The exothermic, enthalpic effect of preferential solvation of cyclic ethers increases with increasing ring size and temperature. The increase in the negative effect of the structural properties of the mixed solvent with increase in the ring size in the process of preferential solvation of the cyclic ethers indicates an increasing disturbance of the mixed solvent structure, which is reflected in the influence of the energetic properties of the mixed solvent.
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Affiliation(s)
- Małgorzata Jóźwiak
- Department of Physical Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 165, 90-236 Lodz, Poland
| | - Monika A Trzmielak
- Department of Physical Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 165, 90-236 Lodz, Poland
| | - Michał Wasiak
- Department of Physical Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 165, 90-236 Lodz, Poland
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2
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Composition of the Solvation Shell of the Selected Cyclic Ethers (1,4-Dioxane, 12-Crown-4, 15-Crown-5 and 18-Crown-6) in a Mixture of Formamide with Water at Four Temperatures. Molecules 2023; 28:molecules28052169. [PMID: 36903417 PMCID: PMC10004068 DOI: 10.3390/molecules28052169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/02/2023] Open
Abstract
The solution enthalpy of 15-crown-5 and 18-crown-6 ethers in the mixture of formamide (F) and water (W) was measured at four temperatures: 293.15 K, 298.15 K, 303.15 K, 308.15 K. The standard molar enthalpy of solution, ΔsolHo, depends on the size of cyclic ethers molecules and the temperature. With increasing temperature, the values of ΔsolHo become less negative. The values of the standard partial molar heat capacity Cp,2o of cyclic ethers at 298.15 K have been calculated. The Cp,2o=f(xW) curve shape indicates the hydrophobic hydration process of cyclic ethers in the range of a high-water content in the mixture with formamide. The enthalpic effect of preferential solvation of cyclic ethers was calculated and the effect of temperature on the preferential solvation process was discussed. The process of complex formation between 18C6 molecules and formamide molecules is observed. The cyclic ethers molecules are preferentially solvated by formamide molecules. The mole fraction of formamide in the solvation sphere of cyclic ethers has been calculated.
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Zhang Z, Shao Y, Tang J, Jiang J, Wang L, Li S. Supramolecular asymmetric catalysis mediated by crown ethers and related recognition systems. GREEN SYNTHESIS AND CATALYSIS 2021. [DOI: 10.1016/j.gresc.2021.03.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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4
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Metwally H, Konermann L. Crown Ether Effects on the Location of Charge Carriers in Electrospray Droplets: Implications for the Mechanism of Protein Charging and Supercharging. Anal Chem 2018; 90:4126-4134. [DOI: 10.1021/acs.analchem.8b00099] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Haidy Metwally
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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5
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Pan W, Mao L, Shi M, Fu Y, Jiang X, Feng W, He Y, Xu D, Yuan L. The cytochrome c–cyclo[6]aramide complex as a supramolecular catalyst in methanol. NEW J CHEM 2018. [DOI: 10.1039/c7nj02741a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A hydrogen-bonded aromatic amide macrocycle forms a host–guest complex with cytochrome c, which acts as a supramolecular catalyst for the oxidation of benzhydrol even at low temperatures.
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Affiliation(s)
- Wang Pan
- College of Chemistry, Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University
- Chengdu 610064
- China
| | - Lijun Mao
- College of Chemistry, Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University
- Chengdu 610064
- China
| | - Mingsong Shi
- College of Chemistry, Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University
- Chengdu 610064
- China
| | - Yonghong Fu
- College of Chemistry, Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University
- Chengdu 610064
- China
| | - Xiaomin Jiang
- College of Chemistry, Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University
- Chengdu 610064
- China
| | - Wen Feng
- College of Chemistry, Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University
- Chengdu 610064
- China
| | - Youzhou He
- Chongqing Key Laboratory of Catalysis & Functional Organic Molecules, College of Environment and Resources, Chongqing Technology and Business University
- Chongqing 400067
- China
| | - Dingguo Xu
- College of Chemistry, Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University
- Chengdu 610064
- China
| | - Lihua Yuan
- College of Chemistry, Key Laboratory for Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University
- Chengdu 610064
- China
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6
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Alvarez-Paggi D, Hannibal L, Castro MA, Oviedo-Rouco S, Demicheli V, Tórtora V, Tomasina F, Radi R, Murgida DH. Multifunctional Cytochrome c: Learning New Tricks from an Old Dog. Chem Rev 2017; 117:13382-13460. [DOI: 10.1021/acs.chemrev.7b00257] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Damián Alvarez-Paggi
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
| | - Luciana Hannibal
- Department
of Pediatrics, Universitätsklinikum Freiburg, Mathildenstrasse 1, Freiburg 79106, Germany
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - María A. Castro
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
| | - Santiago Oviedo-Rouco
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
| | - Veronica Demicheli
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Veronica Tórtora
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Florencia Tomasina
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Rafael Radi
- Departamento
de Bioquímica and Center for Free Radical and Biomedical Research,
Facultad de Medicina, Universidad de la República, Av.
Gral. Flores 2125, Montevideo 11800, Uruguay
| | - Daniel H. Murgida
- Departamento
de Química Inorgánica, Analítica y Química
Física and INQUIMAE (CONICET-UBA), Facultad de Ciencias Exactas
y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pab. 2, piso 1, Buenos Aires C1428EHA, Argentina
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7
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Abstract
An artificial peroxidase with thermal tolerance and high catalytic activity has been successfully prepared by mutagenesis of an electron transfer protein, cytochrome c552 from Thermus thermophilus. The mutant enzymes were rationally designed based on the general peroxidase mechanism and spectroscopic analyses of an active intermediate formed in the catalytic reaction. Stopped flow UV-vis spectroscopy and EPR spectroscopy with a rapid freezing sample technique revealed that the initial double mutant, V49D/M69A, which was designed to reproduce the peroxidase mechanism, formed an active oxo-ferryl heme intermediate with a protein radical predominantly localized on Tyr45 during the catalytic reaction. The magnetic power saturation measurement obtained from EPR studies showed little interaction between the oxo-ferryl heme and the tyrosyl radical. Kinetics studies indicated that the isolated oxo-ferryl heme component in the active intermediate was a possible cause of heme degradation during the reaction with H2O2. Strong interaction between the oxo-ferryl heme and the radical was achieved by replacing Tyr45 with tryptophan (resulting in the Y45W/V49D/M69A mutant), which was similar to a tryptophanyl radical found in active intermediates of some catalase-peroxidases. Compared to the protein radical intermediates of V49D/M69A mutant, those of the Y45W/V49D/M69A mutant showed higher reactivity to an organic substrate than to H2O2. The Y45W/V49D/M69A mutant exhibited improved peroxidase activity and thermal tolerance.
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Affiliation(s)
- Y Watanabe
- Research Center of Materials Science, Nagoya University, Nagoya, Japan
| | - H Nakajima
- Graduate School of Science, Osaka City University, Osaka, Japan.
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Srour H, Le Maux P, Chevance S, Simonneaux G. Metal-catalyzed asymmetric sulfoxidation, epoxidation and hydroxylation by hydrogen peroxide. Coord Chem Rev 2013. [DOI: 10.1016/j.ccr.2013.05.010] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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9
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Ariga K, Ito H, Hill JP, Tsukube H. Molecular recognition: from solution science to nano/materials technology. Chem Soc Rev 2012; 41:5800-35. [PMID: 22773130 DOI: 10.1039/c2cs35162e] [Citation(s) in RCA: 332] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In the 25 years since its Nobel Prize in chemistry, supramolecular chemistry based on molecular recognition has been paid much attention in scientific and technological fields. Nanotechnology and the related areas seek breakthrough methods of nanofabrication based on rational organization through assembly of constituent molecules. Advanced biochemistry, medical applications, and environmental and energy technologies also depend on the importance of specific interactions between molecules. In those current fields, molecular recognition is now being re-evaluated. In this review, we re-examine current trends in molecular recognition from the viewpoint of the surrounding media, that is (i) the solution phase for development of basic science and molecular design advances; (ii) at nano/materials interfaces for emerging technologies and applications. The first section of this review includes molecular recognition frontiers, receptor design based on combinatorial approaches, organic capsule receptors, metallo-capsule receptors, helical receptors, dendrimer receptors, and the future design of receptor architectures. The following section summarizes topics related to molecular recognition at interfaces including fundamentals of molecular recognition, sensing and detection, structure formation, molecular machines, molecular recognition involving polymers and related materials, and molecular recognition processes in nanostructured materials.
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Affiliation(s)
- Katsuhiko Ariga
- Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Go-bancho, Chiyoda-ku, Tokyo 102-0076, Japan
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Oshima T, Muto H, Baba Y. Dominant structural factors for complexation and denaturation of proteins using carboxylic acid receptors. Anal Chim Acta 2012; 710:102-10. [PMID: 22123118 DOI: 10.1016/j.aca.2011.10.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 09/30/2011] [Accepted: 10/13/2011] [Indexed: 10/16/2022]
Abstract
Complexation accompanied by denaturation of protein with synthetic carboxylic acid receptors was investigated, to evaluate the key factors for recognition of proteins. The synthetic receptors used were tetraphenylporphyrin (TPP) derivatives and receptors bearing multiple (2-8) carboxylic acid groups. The complexation behavior was quantified from the absorption in the far UV CD spectrum attributed to the secondary structure of the protein. TPP derivatives bearing multiple carboxylic acid groups in the side chains exhibited higher affinity than other receptors that were smaller and had fewer carboxylic acid groups. As the degree of complexation was influenced by the pH and ionic strength in aqueous solution, electrostatic interaction was one of the most important factors for the recognition of proteins. Complexation was also estimated by observation of fluorescence quenching of the TPP derivatives. The stoichiometry of the complexes between lysozyme and the porphyrins was investigated by quantitative analysis of the denaturation using CD spectra. From the results of Job plots and slope analysis for the amount of denatured protein, formation of 1:1 complexes was confirmed. The equilibrium association constants (K(ass)) for lysozyme and the TPP receptors ranged from 0.6×10(6) to 1.1×10(6)M(-1). The lytic activity of lysozyme was partially lost in the presence of anionic TPP derivatives, due to complexation and denaturation.
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Affiliation(s)
- Tatsuya Oshima
- Department of Applied Chemistry, Faculty of Engineering, University of Miyazaki, Nishi, Miyazaki, Japan.
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11
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Oshima T, Baba Y. Recognition of exterior protein surfaces using artificial ligands based on calixarenes, crown ethers, and tetraphenylporphyrins. J INCL PHENOM MACRO 2011. [DOI: 10.1007/s10847-011-0088-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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12
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Shinoda S, Tsukube H. Molecular recognition of cytochrome c by designed receptors for generation of in vivo and in vitro functions. Chem Sci 2011. [DOI: 10.1039/c1sc00162k] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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13
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Lu Y, Lu W, Wang W, Guo Q, Yang Y. Thermodynamic studies of partitioning behavior of cytochrome c in ionic liquid-based aqueous two-phase system. Talanta 2011; 85:1621-6. [PMID: 21807231 DOI: 10.1016/j.talanta.2011.06.058] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Revised: 06/20/2011] [Accepted: 06/22/2011] [Indexed: 11/28/2022]
Abstract
The ionic liquid/aqueous two-phase extraction systems (ATPSs) based on imidazolium ionic liquids were used to extract cytochrome c. Effects of the alkyl chain length of the ionic liquid cations, concentration of potassium citrate, temperature and pH on the extraction efficiency have been investigated. The thermodynamic parameters (ΔG(T)°, ΔH(T)° and ΔS(T)°) associated with Cyt-c partitioning in aqueous two phase systems were determined. Thermodynamic studies indicated that the partitioning of Cyt-c was driven by both hydrophobic and electrostatic interactions in the extraction process. Under the optimum conditions, experiment results showed that 94% of the cytochrome c could be extracted into the ionic liquid-rich phase in a one-step extraction. The structural characterization of Cyt-c in the IL ATPS was investigated by UV-vis and circular dichroism (CD) spectra. The results demonstrated that no direct bonding interaction observed between ionic liquid and cytochrome c, while the native properties of the cytochrome c were not altered. Compared with traditional liquid-liquid extractions based on toxic organic solvents, ionic liquid/aqueous two phase extraction offers clear advantages due to no use of volatile organic solvent and low consumption of imidazolium ionic liquids.
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Affiliation(s)
- Yanmin Lu
- Key Laboratory for Special Functional Aggregated Materials of Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan, PR China
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14
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Wojaczyńska E, Wojaczyński J. Enantioselective synthesis of sulfoxides: 2000-2009. Chem Rev 2010; 110:4303-56. [PMID: 20415478 DOI: 10.1021/cr900147h] [Citation(s) in RCA: 324] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Elzbieta Wojaczyńska
- Department of Organic Chemistry, Faculty of Chemistry, Wrocław University of Technology, Wybrzeze Wyspiańskiego 27, 50 370 Wrocław, Poland.
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15
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Extraction and separation of a lysine-rich protein by formation of supramolecule between crown ether and protein in aqueous two-phase system. Anal Chim Acta 2010; 674:211-9. [DOI: 10.1016/j.aca.2010.06.039] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 05/12/2010] [Accepted: 06/27/2010] [Indexed: 11/15/2022]
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16
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Nakajima H, Ramanathan K, Kawaba N, Watanabe Y. Rational engineering of Thermus thermophilus cytochrome c552 to a thermally tolerant artificial peroxidase. Dalton Trans 2010; 39:3105-14. [DOI: 10.1039/b924365h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Nakajima H, Ichikawa Y, Satake Y, Takatani N, Manna SK, Rajbongshi J, Mazumdar S, Watanabe Y. Engineering ofThermus thermophilusCytochromec552: Thermally Tolerant Artificial Peroxidase*. Chembiochem 2008; 9:2954-7. [DOI: 10.1002/cbic.200800599] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Shimojo K, Kamiya N, Tani F, Naganawa H, Naruta Y, Goto M. Extractive solubilization, structural change, and functional conversion of cytochrome c in ionic liquids via crown ether complexation. Anal Chem 2007; 78:7735-42. [PMID: 17105166 DOI: 10.1021/ac0612877] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This article reports on the extraction behavior of heme proteins from an aqueous phase into ionic liquids (ILs) with dicyclohexano-18-crown-6 (DCH18C6), and the structure-function relationship of cytochrome c (Cyt-c) dissolved in ILs. We have found that DCH18C6 enables transfer of Lys-rich proteins into ILs via supramolecular complexation. The hydrophobicity and functional groups of ILs have a great influence on protein partitioning, and a hydroxyl group-containing IL with DCH18C6 is capable of the quantitative partitioning of Cyt-c. On the other hand, protein transfer using conventional organic solvents is negligibly small. UV-visible, CD, and resonance Raman spectroscopic characterizations indicate that the sixth ligand Met 80 in the heme group of the Cyt-c-DCH18C6 complex in IL is replaced by other amino acid residues of the peptide chain and that a non-natural, six-coordinate, low-spin ferric heme structure is induced in IL. Solubilization of Cyt-c in IL causes the environmental change of the heme vicinity of Cyt-c, which triggers the functional conversion of Cyt-c from an electron-transfer protein to peroxidase. The Cyt-c-DCH18C6 complex in IL provides remarkably high peroxidase activity compared with native Cyt-c, because of enhancement of the affinity for H2O2.
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Affiliation(s)
- Kojiro Shimojo
- Division of Environment and Radiation Sciences, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, Tokai-mura, Ibaraki, 319-1195, Japan. shimojo.kojiro@ jaea.go.jp
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Ly T, Julian RR. Using ESI-MS to probe protein structure by site-specific noncovalent attachment of 18-crown-6. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2006; 17:1209-15. [PMID: 16766206 DOI: 10.1016/j.jasms.2006.05.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Revised: 05/15/2006] [Accepted: 05/17/2006] [Indexed: 05/10/2023]
Abstract
A new method for probing the equilibrium structures and folding states of proteins utilizing electrospray ionization mass spectrometry is described. Protein structure is explored as a function of side-chain availability as determined by a specific interaction between lysine and 18-crown-6 ether (18C6). Various intramolecular interactions are competitive with the lysine/18C6 interaction and can prevent noncovalent attachment of 18C6. Changes to protein structure modify these inhibiting intramolecular interactions, which leads to a change in the number of 18C6s that attach to the protein. Experiments conducted with cytochrome c, ubiquitin, and melittin reveal that the method is sensitive to changes in both tertiary and secondary structure. In addition, the structure of each charge state can be examined independently. Experiments can be performed under conditions where the pH and amount of organic cosolvent are varied. Control experiments conducted with pentalysine, which lacks structural organization, are also presented.
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Affiliation(s)
- Tony Ly
- Department of Chemistry, University of California, Riverside, California, USA
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Shimojo K, Nakashima K, Kamiya N, Goto M. Crown Ether-Mediated Extraction and Functional Conversion of Cytochrome c in Ionic Liquids. Biomacromolecules 2005; 7:2-5. [PMID: 16398488 DOI: 10.1021/bm050847t] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report that a macrocyclic ligand enables transfer of a protein from an aqueous phase to ionic liquids. The extraction behavior of heme protein cytochrome c (Cyt-c) from an aqueous phase into ionic liquids was investigated with crown ethers. A hydroxyl-group-containing ionic liquid with dicyclohexano-18-crown-6 was found to be capable of quantitative partitioning of Cyt-c, whereas the protein transfer using conventional organic solvents was negligibly small. Furthermore, we clarified that Cyt-c solubilized in ionic liquids caused a structural transformation of Cyt-c, which triggers its functional conversion from an electron-transfer protein to peroxidase.
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Affiliation(s)
- Kojiro Shimojo
- Division of Environment and Radiation Sciences, Nuclear Science and Energy Directorate, Japan Atomic Energy Agency, Tokai-mura, Ibaraki 319-1195, Japan
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