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Parodi F, Cacciari RD, Mazalu JN, Montejano HA, Reynoso E, Biasutti MA. UVB light influence on the laccase enzyme catalytic activity in reverse micelles and in homogeneous aqueous medium. Amino Acids 2023; 55:469-479. [PMID: 36695918 DOI: 10.1007/s00726-023-03237-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 01/09/2023] [Indexed: 01/26/2023]
Abstract
Laccase is a versatile enzyme widely used for the oxidation of environmental contaminants and exhibits great potential in many others applications; however, it undergoes photo-degradation when irradiated with UVB light. The photo-stability of this biomolecule can be improved by immobilization in different encapsulation media and reverse micelles have been employed with this purpose. The laccase activity using syringaldazine as substrate has been studied in the absence and in the presence of reverse micelles of 0.15 M of sodium 1,4-bis (2-ethylhexyl) sulfosuccinate (AOT) in isooctane at W0 ([H2O]/[AOT]) = 30, before and after irradiation of the enzyme with UVB light. The kinetic parameters, i.e., Michaelis-Menten constant (KM), catalytic constant (kCAT), and catalytic efficiency (kCAT/KM), were determined by spectroscopic measurements in the micellar system and in homogeneous aqueous medium. The distribution of the substrate in two pseudo-phases (micelle and organic solvent) was taking into account in the kinetic parameters' determinations. The results obtained indicate that the nano-aggregate system confers a solubilization media in the water core of the micelle, both for the enzyme and the substrate, in which the catalytic function of the enzyme is preserved. On the other hand, in homogeneous aqueous medium kCAT/KM value, it is reduced by ~50% after UVB irradiation of the enzyme, while in micellar medium, less than 10% of the activity was affected. This mean that the enzyme achieves a considerably photo-protection when it is irradiated with UVB light in reverse micelles as compared with the homogeneous aqueous medium. This phenomenon can be mainly due to the confinement of the biomolecule inside the micelle. Physical properties of the nano-environment could affect photochemical reactions.
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Affiliation(s)
- Facundo Parodi
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina
- Instituto Para El Desarrollo Agroindustrial y de la Salud (IDAS), CONICET-UNRC, Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina
| | - R Daniel Cacciari
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CONICET-UNLP, Diagonal 113 y 64, Casco Urbano, B1900, La Plata, Buenos Aires, Argentina
| | - Jeremías N Mazalu
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina
| | - Hernán A Montejano
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina
- Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), CONICET-UNRC, Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina
| | - Eugenia Reynoso
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina.
- Instituto Para El Desarrollo Agroindustrial y de la Salud (IDAS), CONICET-UNRC, Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina.
| | - M Alicia Biasutti
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto (UNRC), Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina.
- Instituto Para El Desarrollo Agroindustrial y de la Salud (IDAS), CONICET-UNRC, Ruta Nacional 36 Km 601, X5804BYA, Río Cuarto, Córdoba, Argentina.
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Wang C, Xiong MC, Zhao X, Liu KH. Kinetics study on reaction of atenolol with singlet oxygen by directly monitoring the 1O2 phosphorescence. CHINESE J CHEM PHYS 2021. [DOI: 10.1063/1674-0068/cjcp2103037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Chen Wang
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ming-chen Xiong
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Xuan Zhao
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Kun-hui Liu
- College of Chemistry, Beijing Normal University, Beijing 100875, China
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Effect of UVB solar irradiation on Laccase enzyme: evaluation of the photooxidation process and its impact over the enzymatic activity for pollutants bioremediation. Amino Acids 2020; 52:925-939. [PMID: 32556742 DOI: 10.1007/s00726-020-02861-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 06/13/2020] [Indexed: 12/29/2022]
Abstract
The multi-copper Laccase enzyme corresponds to one of the most investigated oxidoreductases for potential uses in xenobiotic bioremediation. In this work, we have investigated the photo-degradation process of Laccase from Trametesversicolor induced by UVB light and the influence on its activity over selected substrates. Laccase undergoes photo-degradation when irradiated with UVB light, and the process depends on the presence of oxygen in the medium. With the kinetic data obtained from stationary and time resolved measurements, a photo-degradation mechanism of auto-sensitization was proposed for the enzyme. Laccase generates singlet oxygen, by UVB light absorption, and this reactive oxygen species can trigger the photo-oxidation of susceptible amino acids residues present in the protein structure. The catalytic activity of Laccase was evaluated before and after UVB photolysis over hydroxy-aromatic compounds and substituted phenols which represent potential pollutants. The dye bromothymol blue, the antibiotic rifampicin and the model compound syringaldazine, were selected as substrates. The values of the kinetic parameters determined in our experiments indicate that the photo-oxidative process of Laccase has a very negative impact on its overall catalytic function. Despite this, we have not found evidence of structural damage by SDS-PAGE and circular dichroism experiments, which indicate that the enzyme retained its secondary structure. We believe that, given the importance of Laccase in environmental bioremediation, the information found about the stability of this kind of biomolecule exposed to UV solar irradiation may be relevant in the technological design and/or optimization of decontamination strategies.
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Reynoso E, Cacciari RD, Suchetti CA, Montejano HA, Biasutti MA. Influence of pH and micellar systems on the sensitized photo-oxidation of bovine serum albumin. LUMINESCENCE 2019; 34:324-333. [PMID: 30740864 DOI: 10.1002/bio.3610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 01/03/2019] [Accepted: 01/07/2019] [Indexed: 12/24/2022]
Abstract
Photosensitized oxidation of bovine serum albumin (BSA), by using perinaphtenone as a sensitizer, has been studied at pH 7.4 and 11. The selected sensitizer does not present ground-state complexation with BSA and ensures that the mechanism is mediated by O2 (1 △g ). Strong dependence between BSA-O2 (1 △g ) photo-oxidation and the pH of the medium has been found. The relative oxygen uptake rate (v- △ O2 ) and the total quenching rate constant (kt ) values are higher at pH 11 than pH 7.4. The enhancement in the alkaline condition is due to conformational changes in the protein and the reactivity of tyrosinate anion with O2 (1 △g ). Even when the tendency with the pH in the presence of sodium dodecyl sulfate (SDS) micelles is similar to that observed in homogeneous media, an increment on the kt value is detected. This effect may be attributable to the strong interaction of BSA-SDS, which leads to the protein unfolding and could leave more exposed photo-oxidizable amino acids. A protective effect against the O2 (1 △g )-mediated photo-oxidation was observed in reverse micelles (RMs) of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) by comparing the kt values obtained at W = 10 with respect to the one obtain in homogeneous media. The latter could be mainly explained by the modification in the solvent polarity. Also, another important observation was found, the internal pH inside RMs of AOT sensed through tyrosine absorption was independent of the one used for the formation of the water pool. Hence, the kt values observed at both pH, are quite similar.
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Affiliation(s)
- Eugenia Reynoso
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Córdoba, Argentina
| | - R Daniel Cacciari
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Córdoba, Argentina
| | - Carlos A Suchetti
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Córdoba, Argentina
| | - Hernán A Montejano
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Córdoba, Argentina
| | - M Alicia Biasutti
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Córdoba, Argentina
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