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Mansoldo FRP, Berrino E, Guglielmi P, Carradori S, Carta F, Secci D, Supuran CT, Vermelho AB. An innovative spectroscopic approach for qualitative and quantitative evaluation of Mb-CO from myoglobin carbonylation reaction through chemometrics methods. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 267:120602. [PMID: 34801390 DOI: 10.1016/j.saa.2021.120602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/13/2021] [Accepted: 11/07/2021] [Indexed: 06/13/2023]
Abstract
In this work, an innovative approach using K-means and multivariate curve resolution-purity based algorithm (MCR-Purity) for the evaluation and quantification of carboxymyoglobin (Mb-CO) formation from Deoxy-Myoglobin (Deoxy-Mb) was presented. Through a multilevel multifactor experimental design, samples with different concentrations of Mb-CO were created. The UV-Vis spectra of these samples were submitted to K-means analysis, finding 3 clusters. The mean spectra of the clusters were extracted and it was possible to detect 2 totally differentiable groups through peaks 423 and 434 nm, which are wavelengths related to the Mb-CO and Deoxy-Mb components, respectively. The spectral data were subjected to MCR-Purity analysis. The MCR-Purity result successfully described the analyzed reaction, explaining more than 99.9% of the variance (R2) with a LOF of 1.43%. Then, a predictive model of MbCO was created through the linear relationship between MCR-Purity contributions and known concentrations of MbCO. The performance parameters of the created predictive model were R2CV = 0.98, RMSECV = 0.58 and RPDcv = 7.8 for the training set, and R2P = 0.98, RMSEP = 0.7 and RPDp = 6.8 for the test set. Thus, the predictive model presented an excellent performance considering that the Mb-CO variation is comprised between 0 and 21 µM. Therefore, these results demonstrate that the application of the proposed strategy to the analysis of spectral data presenting overlapping bands is feasible and robust.
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Affiliation(s)
- Felipe R P Mansoldo
- Federal University of Rio de Janeiro (UFRJ), Institute of Microbiology Paulo de Góes, BIOINOVAR - Biocatalysis, Bioproducts and Bioenergy, Rio de Janeiro, Brazil
| | - Emanuela Berrino
- Università degli Studi di Firenze, NEUROFARBA Dept., Sezione di Scienze Farmaceutiche, Via Ugo Schiff 6, 50019 Sesto Fiorentino (Florence), Italy; Department of Drug Chemistry and Technologies, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Paolo Guglielmi
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Simone Carradori
- Department of Pharmacy, "G. d'Annunzio" University of Chieti-Pescara, via dei Vestini 31, 66100 Chieti, Italy
| | - Fabrizio Carta
- Università degli Studi di Firenze, NEUROFARBA Dept., Sezione di Scienze Farmaceutiche, Via Ugo Schiff 6, 50019 Sesto Fiorentino (Florence), Italy
| | - Daniela Secci
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy
| | - Claudiu T Supuran
- Università degli Studi di Firenze, NEUROFARBA Dept., Sezione di Scienze Farmaceutiche, Via Ugo Schiff 6, 50019 Sesto Fiorentino (Florence), Italy
| | - Alane B Vermelho
- Federal University of Rio de Janeiro (UFRJ), Institute of Microbiology Paulo de Góes, BIOINOVAR - Biocatalysis, Bioproducts and Bioenergy, Rio de Janeiro, Brazil.
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Determination of the formal redox potentials of the cyanhaemoglobin/cyanmethaemoglobin and the myoglobin/metmyoglobin couples at neutral pH. Bioelectrochemistry 2017; 120:83-86. [PMID: 29197256 DOI: 10.1016/j.bioelechem.2017.11.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/23/2017] [Accepted: 11/23/2017] [Indexed: 11/22/2022]
Abstract
Determination of a representative formal redox potential of the Fe(II)/Fe(III) redox couple in cyanhaemoglobin, at pH=7 and related to the state in solution, was the objective of this work. It was achieved at low concentrations of the protein (5μM) to circumvent undesired adsorption. Square-wave voltammetry instead of classical cyclic voltammetry was applied because this method is more sensitive and provides information on the formal redox potential and reversibility, even for rapid processes. We obtained E°'=-0.12±0.01V for cyanhaemoglobin and E°'=-0.10±0.01V, vs. SHE, for myoglobin in comparison. These values differ by only 20mV because the two Fe(II)/Fe(III) redox centres are embedded in closely resembling chemical environments. The small difference is probably owed to the additional axially coordinating cyanide ligand in cyanmethaemoglobin which slightly favours the Fe(III) state in the haem macrocycle.
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Khoshtariya DE, Dolidze TD, Shushanyan M, van Eldik R. Long-range electron transfer with myoglobin immobilized at Au/mixed-SAM junctions: mechanistic impact of the strong protein confinement. J Phys Chem B 2014; 118:692-706. [PMID: 24369906 DOI: 10.1021/jp4101569] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Horse muscle myoglobin (Mb) was tightly immobilized at Au-deposited ~15-Å-thick mixed-type (1:1) alkanethiol SAMs, HS-(CH₂)₁₁-COOH/HS-(CH₂)₁₁-OH, and placed in contact with buffered H₂O or D₂O solutions. Fast-scan cyclic voltammetry (CV) and a Marcus-equation-based analysis were applied to determine unimolecular standard rate constants and reorganization free energies for electron transfer (ET), under variable-temperature (15-55 °C) and -pressure (0.01-150 MPa) conditions. The CV signal was surprisingly stable and reproducible even after multiple temperature and pressure cycles. The data analysis revealed the following values: standard rate constant, 33 s⁻¹ (25 °C, 0.01 MPa, H₂O); reorganization free energy, 0.5 ± 0.1 eV (throughout); activation enthalpy, 12 ± 3 kJ mol⁻¹; activation volume, -3.1 ± 0.2 cm³ mol⁻¹; and pH-dependent solvent kinetic isotope effect (k(H)⁰/k(D)⁰), 0.7-1.4. Furthermore, the values for the rate constant and reorganization free energy are very similar to those previously found for cytochrome c electrostatically immobilized at the monocomponent Au/HS-(CH₂)₁₁-COOH junction. In vivo, Mb apparently forms a natural electrostatic complex with cytochrome b₅ (cyt-b₅) through the "dynamic" (loose) docking pattern, allowing for a slow ET that is intrinsically coupled to the water's removal from the "defective" heme iron (altogether shaping the biological repair mechanism for Mb's "met" form). In contrary, our experiments rather mimic the case of a "simple" (tight) docking of the redesigned (mutant) Mb with cyt-b₅ (Nocek et al. J. Am. Chem. Soc. 2010, 132, 6165-6175). According to our analysis, in this configuration, Mb's distal pocket (linked to the "ligand channel") seems to be arrested within the restricted configuration, allowing the rate-determining reversible ET process to be coupled only to the inner-sphere reorganization (minimal elongation/shortening of an Fe-OH₂ bond) rather than the pronounced detachment (rebinding) of water and, hence, to be much faster.
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Affiliation(s)
- Dimitri E Khoshtariya
- Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg , 91058 Erlangen, Germany
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Keesey RL, Ryan MD. Spectroelectrochemical elucidation of the kinetics of two closely spaced electron transfers. J Electroanal Chem (Lausanne) 2012. [DOI: 10.1016/j.jelechem.2012.04.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Jin BK, Li L, Huang JL, Zhang SY, Tian YP, Yang JX. IR Spectroelectrochemical Cyclic Voltabsorptometry and Derivative Cyclic Voltabsorptometry. Anal Chem 2009; 81:4476-81. [DOI: 10.1021/ac9003634] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bao-Kang Jin
- Department of Chemistry, Anhui University, Hefei, 230039 China
| | - Li Li
- Department of Chemistry, Anhui University, Hefei, 230039 China
| | - Jin-Ling Huang
- Department of Chemistry, Anhui University, Hefei, 230039 China
| | - Sheng-Yi Zhang
- Department of Chemistry, Anhui University, Hefei, 230039 China
| | - Yu-Peng Tian
- Department of Chemistry, Anhui University, Hefei, 230039 China
| | - Jia-Xiang Yang
- Department of Chemistry, Anhui University, Hefei, 230039 China
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Interfacial electron transfer kinetics of myoglobins chemically modified with succinic anhydride at an indium oxide electrode. J Electroanal Chem (Lausanne) 2008. [DOI: 10.1016/j.jelechem.2008.06.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Panicco P, Astuti Y, Fantuzzi A, Durrant JR, Gilardi G. P450 versus P420: Correlation between Cyclic Voltammetry and Visible Absorption Spectroscopy of the Immobilized Heme Domain of Cytochrome P450 BM3. J Phys Chem B 2008; 112:14063-8. [DOI: 10.1021/jp8050033] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paola Panicco
- Division of Molecular Biosciences and Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, U.K., and Department of Human and Animal Biology, University of Turin, Italy
| | - Yeni Astuti
- Division of Molecular Biosciences and Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, U.K., and Department of Human and Animal Biology, University of Turin, Italy
| | - Andrea Fantuzzi
- Division of Molecular Biosciences and Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, U.K., and Department of Human and Animal Biology, University of Turin, Italy
| | - James R. Durrant
- Division of Molecular Biosciences and Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, U.K., and Department of Human and Animal Biology, University of Turin, Italy
| | - Gianfranco Gilardi
- Division of Molecular Biosciences and Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, U.K., and Department of Human and Animal Biology, University of Turin, Italy
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Kato D, Xu G, Iwasaki Y, Hirata Y, Kurita R, Niwa O. Heavy phosphate adsorption on amorphous ITO film electrodes: nano-barrier effect for highly selective exclusion of anionic species. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:8400-5. [PMID: 17616215 DOI: 10.1021/la700466y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We prepared an amorphous indium tin oxide (ITO) film and studied it with respect to its surface characterization and the effect of phosphate adsorption on its electrochemical properties. The film was deposited using RF sputtering under ambient low-oxygen conditions at room temperature. The XPS results revealed that the amount of phosphate adsorbed on the amorphous ITO film was more than 4.6 times greater than that adsorbed on commercially available polycrystalline ITO film in spite of the smaller microscopic surface area of the former. Electrochemical responses for anionic species such as L-ascorbic acid (AA) and 3,4-dihydroxyphenylacetic acid (DOPAC) on the phosphate-adsorbed ITO film electrodes were more effectively suppressed at the amorphous ITO film electrode than at the polycrystalline ITO film electrode when a phosphate-containing electrolyte was used. Such suppression could be attributed to the electrostatic repulsion between the anionic species and more heavily adsorbed phosphate on our amorphous ITO film electrode surface. This effect is made more pronounced by increasing the phosphate concentration to 1 mM. With 1 mM phosphate, the amorphous ITO film electrode showed the highest selectivity for dopamine (DA) against the anionic species, namely, 880 for DA/AA and 330 for DA/DOPAC, respectively. In contrast, the selectivity was 120 for DA/AA and 20 for DA/DOPAC with the polycrystalline ITO film electrode.
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Affiliation(s)
- Dai Kato
- National Institute of Advanced Industrial Science and Technology, 1-1-1, Higashi, Tsukuba, Ibaraki 305-8566, Japan
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Vaze A, Rusling JF. Microemulsion-controlled reaction sites in biocatalytic films for electrochemical reduction of vicinal dibromides. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:10788-95. [PMID: 17129061 DOI: 10.1021/la061138j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We report herein the electrochemical dehalogenation of vicinal dibromides in microemulsions using cross-linked films of the redox protein myoglobin (Mb) and poly-l-lysine (PLL) covalently bonded to carbon electrodes. Catalytic reduction of the dibromides to olefins was more efficient in an SDS microemulsion than in a CTAB microemulsion. SDS shifts the Mb redox potential more negative, but a comparison to Mb-SDS films suggests that the activation free energy of the reduction is controlled by an inner-sphere mechanism. SDS also enters the positively charged Mb-PLL films and preconcentrates the dibromide reactants, enhancing catalytic efficiency in SDS microemulsions. Shifts in formal potential and Soret absorbance bands for Mb-PLL films suggested binding of trans-1,2-dibromocyclohexane in the iron heme distal pocket with little catalysis. Results are consistent with active catalytic reduction sites for reactant bound on the protein surface and less-reactive sites in the distal heme pocket. Preconcentration into catalytic PLL films using SDS incorporated from microemulsions may be a general way to improve catalytic efficiency for nonpolar reactants in microemulsions.
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Affiliation(s)
- Abhay Vaze
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, USA
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Electrochemical analysis of heme functions of myoglobin using semi-artificial myoglobins. J Electroanal Chem (Lausanne) 2006. [DOI: 10.1016/j.jelechem.2005.01.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Ray A, Feng M, Tachikawa H. Direct electrochemistry and Raman spectroscopy of sol-gel-encapsulated myoglobin. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:7456-60. [PMID: 16042479 DOI: 10.1021/la050422s] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The direct electrochemistry of myoglobin (Mb) has been observed at a glassy carbon (GC) electrode coated with silica sol-gel-encapsulated Mb film. A well-behaved cyclic voltammogram is observed with a midpoint potential (E(1/2)) of -0.25 V vs Ag/AgCl in a pH 7.0 phosphate buffer. This potential, which is pH-dependent, is 70-90 mV more negative than the formal potential values obtained by using the spectroeletrochemical titration method at the same pH. Square wave voltametry (SWV) also shows a peak potential of -0.25 V for the reduction of Mb under the same experimental conditions. Both cathodic and anodic peak currents have a linear relationship with the scan rate. The midpoint potential decreases with pH, having a slope of -30 mV/pH. UV-vis and resonance Raman spectroscopic studies reveal that the sol-gel provides a bio-compatible environment where Mb retains a structure similar to its solution form, a 6-coordinated aquomet myoglobin. These results suggest that the silica sol-gel is a useful matrix for studying direct electrochemistry of other heme proteins.
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Affiliation(s)
- Anandhi Ray
- Department of Chemistry, Jackson State University, 1400 J.R. Lynch Street, Jackson, Mississippi 39217, USA
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Mie Y, Mizutani F, Uno T, Yamada C, Nishiyama K, Taniguchi I. Direct electrochemistry of engineered cytochrome b562 molecules with a ligand binding pocket. J Inorg Biochem 2005; 99:1245-9. [PMID: 15833348 DOI: 10.1016/j.jinorgbio.2005.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2004] [Revised: 02/18/2005] [Accepted: 03/01/2005] [Indexed: 11/18/2022]
Abstract
The rapid and reversible electron transfer reaction of cytochrome b562 was observed at an In2O3 electrode. The estimated heterogeneous electron transfer rate constant (k0') was k0' > or = 5.0 x 10(-3) cm s(-1) at pH 6.5. When the methionine-7 (Met-7) residue, which coordinates to the heme iron as an axial ligand, of the wild-type cytochrome b562 was replaced by an Ala or Gly residue, a water molecule bound to the heme iron and the electron transfer rate constants decreased to 1.3 x 10(-3) and 1.8 x 10(-3) cm s(-1), respectively. This decrease in the electron transfer rate would be due to the larger reorganization energy for the structural change at the redox site. The midpoint potential of cytochrome b562 was shifted negatively by approximately 135 mV by replacing Met-7 with Ala or Gly. Similar dissociation kinetics of cyanide for the mutated molecules as compared to native myoglobin was obtained.
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Affiliation(s)
- Yasuhiro Mie
- National Institute of Advanced Industrial Science and Technology, 2-17-2-1, Tsukisamu-higashi, Toyohira, Sapporo 062-8517, Japan.
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Mie Y, Yamada C, Hareau GPJ, Neya S, Uno T, Funasaki N, Nishiyama K, Taniguchi I. Functional Evaluation of Heme Vinyl Groups in Myoglobin with Symmetric Protoheme Isomers. Biochemistry 2004; 43:13149-55. [PMID: 15476408 DOI: 10.1021/bi049051p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We replaced protoheme-IX in native myoglobin with the symmetric protohemes-III and -XIII, in order to investigate the role of heme vinyl-globin contacts on Mb function. The UV-visible spectra and the resonance Raman spectra in the high-frequency region (containing oxidation, spin, and coordination state marker lines) of the two reconstituted Mbs were very similar. However, the signal intensity of the Soret band in the CD spectra and the resonance Raman lines for vinyl bending modes in the low-frequency region notably differed, thereby reflecting altered heme peripheral contacts. The redox potentials, formal heterogeneous electron-transfer rates, and thermal denaturation temperatures of the two reconstituted Mbs were also indistinguishable. In addition, the oxygen binding properties of the ferrous deoxy Mbs were comparable. These results demonstrate that altered heme vinyl-globin interactions only slightly affect the physical properties of Mb. It is therefore likely that the orientation of protoheme-IX about the alpha,gamma-axis in the heme pocket is not necessarily a crucial factor for oxygen binding to native Mb.
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Affiliation(s)
- Yasuhiro Mie
- Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1, Oe-honmachi, Kumamoto 862-0973, Japan.
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Astuti Y, Topoglidis E, Briscoe PB, Fantuzzi A, Gilardi G, Durrant JR. Proton-coupled electron transfer of flavodoxin immobilized on nanostructured tin dioxide electrodes: thermodynamics versus kinetics control of protein redox function. J Am Chem Soc 2004; 126:8001-9. [PMID: 15212550 DOI: 10.1021/ja0496470] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this paper, we report a spectroelectrochemical investigation of proton-coupled electron transfer in flavodoxin D. vulgaris Hildenborough (Fld). Poly-L-lysine is used to promote the binding of Fld to the nanocrystalline, mesoporous SnO(2) electrodes. Two reversible redox couples of the immobilized Fld are observed electrochemically and are assigned by spectroelectrochemistry to the quinone/semiquinone and semiquinone/hydroquinone couples of the protein's flavin mononucleotide (FMN) redox cofactor. Comparison with control data for free FMN indicates no contamination of the Fld data by dissociated FMN. The quinone/semiquinone and semiquinone/hydroquinone midpoint potentials (E(q/sq) and E(sq/hq)) at pH 7 were determined to be -340 and -585 mV vs Ag/AgCl, in good agreement with the literature. E(q/sq) exhibited a pH dependence of 51 mV/pH. The kinetics of these redox couples were studied using cyclic voltammetry, cyclic voltabsorptometry, and chronoabsorptometry. The semiquinone/quinone reoxidation is found to exhibit slow, potential-independent but pH-sensitive kinetics with a reoxidation rate constant varying from 1.56 s(-)(1) at pH 10 to 0.0074 s(-)(1) at pH 5. The slow kinetics are discussed in terms of a simple kinetics model and are assigned to the reoxidation process being rate limited by semiquinone deprotonation. It is proposed that this slow deprotonation step has the physiological benefit of preventing the undesirable loss of reducing equivalents which results from semiquinone oxidation to quinone.
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Affiliation(s)
- Yeni Astuti
- Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, UK
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Abstract
The titratable potentiometric response of hemoglobin (Hb) induced by adenosine-5'-triphosphate (ATP) is observed. The concentration-dependent effect of ATP on the anaerobic redox reaction of the protein at pH 7.0 reflects that ATP will induce stabilization of the reduced state and destabilization of the R-like (met Fe(III)) state of the metHb, when ATP concentration is lower than 3.0 mM. But when ATP concentration is between 4 and 7 mM, shift of the oxidation potential may also be observed. With reference to the study of adenosine, adenosine-5'-monophosphate, adenosine-5'-diphosphate and 2,3-diphosphoglycerate, the allosteric effect of ATP on Hb is discussed extensively. This study has given an electrochemical approach to the investigation of effect of ATP, an in vivo allosteric effector, on Hb in the physiological concentration range.
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Affiliation(s)
- Weilin Peng
- Department of Biochemistry and National Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, PR China
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Osyczka A, Moser CC, Dutton PL. Novel cyanide inhibition at cytochrome c1 of Rhodobacter capsulatus cytochrome bc1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2004; 1655:71-6. [PMID: 15100019 DOI: 10.1016/j.bbabio.2003.07.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2003] [Revised: 07/14/2003] [Accepted: 07/14/2003] [Indexed: 11/18/2022]
Abstract
Oxidized cytochrome c(1) in photosynthetic bacterium Rhodobacter capsulatus cytochrome bc(1) reversibly binds cyanide with surprisingly high, micromolar affinity. The binding dramatically lowers the redox midpoint potential of heme c(1) and inhibits steady-state turnover activity of the enzyme. As cytochrome c(1), an auxiliary redox center of the high-potential chain of cytochrome bc(1), does not interact directly with the catalytic quinone/quinol binding sites Q(o) and Q(i), cyanide introduces a novel, Q-site independent locus of inhibition. This is the first report of a reversible inhibitor that manipulates the energetics and electron transfers of the high-potential redox chain of cytochrome bc(1), while maintaining quinone substrate catalytic sites in an intact form.
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Affiliation(s)
- Artur Osyczka
- The Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, 1004 Stellar-Chance Building, 422 Curie Boulevard, Philadelphia, PA 19104, USA.
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Corry B, Uilk J, Crawley C. Probing direct binding affinity in electrochemical antibody-based sensors. Anal Chim Acta 2003. [DOI: 10.1016/j.aca.2003.01.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Zhang W, Fan C, Sun Y, Li G. An electrochemical investigation of ligand-binding abilities of film-entrapped myoglobin. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1623:29-32. [PMID: 12957714 DOI: 10.1016/s0304-4165(03)00156-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Film-entrapped myoglobin exhibits well-defined electrochemistry which, upon ligand binding, displays a titratable redox potential shift. This effect has been observed to be highly dependent on the charged state of involved films. We have demonstrated that this approach may act as a model system for studies of molecular recognition between proteins and ligands.
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Affiliation(s)
- Wenjun Zhang
- Department of Biochemistry and National Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, PR China
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Souza SR, Dutra RF, Correia MTS, Pessoa MMA, Lima-Filho JL, Coelho LCBB. Electrochemical potential of free and immobilized Cratylia mollis seed lectin. BIORESOURCE TECHNOLOGY 2003; 88:255-258. [PMID: 12618049 DOI: 10.1016/s0960-8524(03)00011-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The electrochemical potentials for free or immobilized Cratylia mollis seed lectin (Cra) were obtained through potentiostatic techniques. A saline solution was used as support to control the charge distribution between saturated calomel electrode and platinum electrode (working electrode). The electrochemical potential to free Cra was determined at the following concentrations: 0.6, 0.9 and 1.0 mg/ml in an aerated environment under different temperatures (5, 10 and 20 degrees C). The best electrochemical potential was obtained with 1.0 mg/ml, at 5 and 10 degrees C, 87 and 102 mV, respectively. Electrochemical potential to Cra immobilized on glass beads activated with 3-aminopropyltriethoxysilane described a linear behavior in relation to the increase in glucose concentration. The development of techniques to define interface electrical parameters will be able to give information about charged groups adsorbed to electrode surface revealing interactions particularly in biological systems.
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Affiliation(s)
- S R Souza
- Rural Federal University of Pernambuco, UFRPE, Brazil
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Souza S, Correia M, Pessoa M, Kennedy J, Lima-Filho J, Coelho L. A novel model to characterize the electric double layer of lectins from Cratylia mollis (Camaratu bean) and Canavalia ensiformis adsorbed on metallic surface. Carbohydr Polym 2001. [DOI: 10.1016/s0144-8617(00)00299-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mie Y, Sonoda K, Kishita M, Krestyn E, Neya S, Funasaki N, Taniguchi I. Effect of rapid heme rotation on electrochemistry of myoglobin. Electrochim Acta 2000. [DOI: 10.1016/s0013-4686(00)00366-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Electroanalytical chemistry of myoglobin with modification of distal histidine by cyanated imidazole. J Electroanal Chem (Lausanne) 1999. [DOI: 10.1016/s0022-0728(99)00172-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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The temperature dependence of the kinetics of cyanide dissociation from the cyanide complex of myoglobin studied by cyclic voltammetry. J Electroanal Chem (Lausanne) 1999. [DOI: 10.1016/s0022-0728(99)00142-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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