1
|
Di Rocco G, Battistuzzi G, Ranieri A, Bortolotti CA, Borsari M, Sola M. Thermodynamics and Kinetics of Electron Transfer of Electrode-Immobilized Small Laccase from Streptomyces coelicolor. Molecules 2022; 27:molecules27228079. [PMID: 36432180 PMCID: PMC9692349 DOI: 10.3390/molecules27228079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/14/2022] [Accepted: 11/18/2022] [Indexed: 11/22/2022] Open
Abstract
The thermodynamic and kinetic properties for heterogeneous electron transfer (ET) were measured for the electrode-immobilized small laccase (SLAC) from Streptomyces coelicolor subjected to different electrostatic and covalent protein-electrode linkages, using cyclic voltammetry. Once immobilized electrostatically onto a gold electrode using mixed carboxyl- and hydroxy-terminated alkane-thiolate SAMs or covalently exploiting the same SAM subjected to N-hydroxysuccinimide+1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (NHS-EDC) chemistry, the SLAC-electrode electron flow occurs through the T1 center. The E°' values (from +0.2 to +0.1 V vs. SHE at pH 7.0) are lower by more than 0.2 V compared to the protein either in solution or immobilized with different anchoring strategies using uncharged SAMs. For the present electrostatic and covalent binding, this effect can, respectively, be ascribed to the negative charge of the SAM surfaces and to deletion of the positive charge of Lys/Arg residues due to amide bond formation which both selectively stabilize the more positively charged oxidized SLAC. Observation of enthalpy/entropy compensation within the series indicates that the immobilized proteins experience different reduction-induced solvent reorganization effects. The E°' values for the covalently attached SLAC are sensitive to three acid base equilibria, with apparent pKa values of pKa1ox = 5.1, pKa1red = 7.5, pKa2ox = 8.4, pKa2red = 10.9, pKa2ox = 8.9, pKa2red = 11.3 possibly involving one residue close to the T1 center and two residues (Lys and/or Arg) along with moderate protein unfolding, respectively. Therefore, the E°' value of immobilized SLAC turns out to be particularly sensitive to the anchoring mode and medium conditions.
Collapse
Affiliation(s)
- Giulia Di Rocco
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Gianantonio Battistuzzi
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Antonio Ranieri
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
- Correspondence: (A.R.); (M.B.)
| | - Carlo Augusto Bortolotti
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Marco Borsari
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
- Correspondence: (A.R.); (M.B.)
| | - Marco Sola
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| |
Collapse
|
2
|
Olloqui-Sariego JL, Pérez-Mejías G, Márquez I, Guerra-Castellano A, Calvente JJ, De la Rosa MA, Andreu R, Díaz-Moreno I. Electric field-induced functional changes in electrode-immobilized mutant species of human cytochrome c. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148570. [PMID: 35643148 DOI: 10.1016/j.bbabio.2022.148570] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 04/21/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
Post-translational modifications and naturally occurring mutations of cytochrome c have been recognized as a regulatory mechanism to control its biology. In this work, we investigate the effect of such in vivo chemical modifications of human cytochrome c on its redox properties in the adsorbed state onto an electrode. In particular, tyrosines 48 and 97 have been replaced by the non-canonical amino acid p-carboxymethyl-L-phenylalanine (pCMF), thus mimicking tyrosine phosphorylation. Additionally, tyrosine 48 has been replaced by a histidine producing the natural Y48H pathogenic mutant. Thermodynamics and kinetics of the interfacial electron transfer of wild-type cytochrome c and herein produced variants, adsorbed electrostatically under different local interfacial electric fields, were determined by means of variable temperature cyclic film voltammetry. It is shown that non-native cytochrome c variants immobilized under a low interfacial electric field display redox thermodynamics and kinetics similar to those of wild-type cytochrome c. However, upon increasing the strength of the electric field, the redox thermodynamics and kinetics of the modified proteins markedly differ from those of the wild-type species. The mutations promote stabilization of the oxidized form and a significant increase in the activation enthalpy values that can be ascribed to a subtle distortion of the heme cofactor and/or difference of the amino acid rearrangements rather than to a coarse protein structural change. Overall, these results point to a combined effect of the single point mutations at positions 48 and 97 and the strength of electrostatic binding on the regulatory mechanism of mitochondrial membrane activity, when acting as a redox shuttle protein.
Collapse
Affiliation(s)
- José Luis Olloqui-Sariego
- Departamento de Química Física, Universidad de Sevilla, Profesor García González, 1, 41012 Sevilla, Spain
| | - Gonzalo Pérez-Mejías
- Instituto de Investigaciones Químicas, cicCartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas (CSIC), Américo Vespucio 49, 41092 Sevilla, (Spain)
| | - Inmaculada Márquez
- Departamento de Química Física, Universidad de Sevilla, Profesor García González, 1, 41012 Sevilla, Spain; Instituto de Investigaciones Químicas, cicCartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas (CSIC), Américo Vespucio 49, 41092 Sevilla, (Spain)
| | - Alejandra Guerra-Castellano
- Instituto de Investigaciones Químicas, cicCartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas (CSIC), Américo Vespucio 49, 41092 Sevilla, (Spain)
| | - Juan José Calvente
- Departamento de Química Física, Universidad de Sevilla, Profesor García González, 1, 41012 Sevilla, Spain
| | - Miguel A De la Rosa
- Instituto de Investigaciones Químicas, cicCartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas (CSIC), Américo Vespucio 49, 41092 Sevilla, (Spain)
| | - Rafael Andreu
- Departamento de Química Física, Universidad de Sevilla, Profesor García González, 1, 41012 Sevilla, Spain
| | - Irene Díaz-Moreno
- Instituto de Investigaciones Químicas, cicCartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas (CSIC), Américo Vespucio 49, 41092 Sevilla, (Spain).
| |
Collapse
|
3
|
Pérez-Mejías G, Díaz-Quintana A, Guerra-Castellano A, Díaz-Moreno I, De la Rosa MA. Novel insights into the mechanism of electron transfer in mitochondrial cytochrome c. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214233] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
4
|
Di Rocco G, Battistuzzi G, Borsari M, Bortolotti CA, Ranieri A, Sola M. The enthalpic and entropic terms of the reduction potential of metalloproteins: Determinants and interplay. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.214071] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|