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Abstract
Debate has been simmering for some years regarding the importance of internal thermal motions of enzymes to catalysis. Recent developments in protein design may bring resolution of the more contentious points a little closer.
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Affiliation(s)
- Jeremy R. H. Tame
- Protein Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Suehiro 1-7-29, Tsurumi, Yokohama, 230-0045 Japan
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2
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Cardozo G, Mastrogiovanni M, Zeida A, Viera N, Radi R, Reyes AM, Trujillo M. Mitochondrial Peroxiredoxin 3 Is Rapidly Oxidized and Hyperoxidized by Fatty Acid Hydroperoxides. Antioxidants (Basel) 2023; 12:antiox12020408. [PMID: 36829967 PMCID: PMC9952270 DOI: 10.3390/antiox12020408] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/19/2023] [Accepted: 01/28/2023] [Indexed: 02/11/2023] Open
Abstract
Human peroxiredoxin 3 (HsPrx3) is a thiol-based peroxidase responsible for the reduction of most hydrogen peroxide and peroxynitrite formed in mitochondria. Mitochondrial disfunction can lead to membrane lipoperoxidation, resulting in the formation of lipid-bound fatty acid hydroperoxides (LFA-OOHs) which can be released to become free fatty acid hydroperoxides (fFA-OOHs). Herein, we report that HsPrx3 is oxidized and hyperoxidized by fFA-OOHs including those derived from arachidonic acid and eicosapentaenoic acid peroxidation at position 15 with remarkably high rate constants of oxidation (>3.5 × 107 M-1s-1) and hyperoxidation (~2 × 107 M-1s-1). The endoperoxide-hydroperoxide PGG2, an intermediate in prostanoid synthesis, oxidized HsPrx3 with a similar rate constant, but was less effective in causing hyperoxidation. Biophysical methodologies suggest that HsPrx3 can bind hydrophobic structures. Indeed, molecular dynamic simulations allowed the identification of a hydrophobic patch near the enzyme active site that can allocate the hydroperoxide group of fFA-OOHs in close proximity to the thiolate in the peroxidatic cysteine. Simulations performed using available and herein reported kinetic data indicate that HsPrx3 should be considered a main target for mitochondrial fFA-OOHs. Finally, kinetic simulation analysis support that mitochondrial fFA-OOHs formation fluxes in the range of nM/s are expected to contribute to HsPrx3 hyperoxidation, a modification that has been detected in vivo under physiological and pathological conditions.
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Affiliation(s)
- Giuliana Cardozo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Mauricio Mastrogiovanni
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Ari Zeida
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Nicolás Viera
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Rafael Radi
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Aníbal M. Reyes
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
- Correspondence: (A.M.R.); (M.T.)
| | - Madia Trujillo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
- Correspondence: (A.M.R.); (M.T.)
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Dasgupta S, Herbert JM. Using Atomic Confining Potentials for Geometry Optimization and Vibrational Frequency Calculations in Quantum-Chemical Models of Enzyme Active Sites. J Phys Chem B 2020; 124:1137-1147. [PMID: 31986049 DOI: 10.1021/acs.jpcb.9b11060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Quantum-chemical studies of enzymatic reaction mechanisms sometimes use truncated active-site models as simplified alternatives to mixed quantum mechanics molecular mechanics (QM/MM) procedures. Eliminating the MM degrees of freedom reduces the complexity of the sampling problem, but the trade-off is the need to introduce geometric constraints in order to prevent structural collapse of the model system during geometry optimizations that do not contain a full protein backbone. These constraints may impair the efficiency of the optimization, and care must be taken to avoid artifacts such as imaginary vibrational frequencies. We introduce a simple alternative in which terminal atoms of the model system are placed in soft harmonic confining potentials rather than being rigidly constrained. This modification is simple to implement and straightforward to use in vibrational frequency calculations, unlike iterative constraint-satisfaction algorithms, and allows the optimization to proceed without constraint even though the practical result is to fix the anchor atoms in space. The new approach is more efficient for optimizing minima and transition states, as compared to the use of fixed-atom constraints, and also more robust against unwanted imaginary frequencies. We illustrate the method by application to several enzymatic reaction pathways where entropy makes a significant contribution to the relevant reaction barriers. The use of confining potentials correctly describes reaction paths and facilitates calculation of both vibrational zero-point and finite-temperature entropic corrections to barrier heights.
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Affiliation(s)
- Saswata Dasgupta
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
| | - John M Herbert
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
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Planas F, Sheng X, McLeish MJ, Himo F. A Theoretical Study of the Benzoylformate Decarboxylase Reaction Mechanism. Front Chem 2018; 6:205. [PMID: 29998094 PMCID: PMC6028569 DOI: 10.3389/fchem.2018.00205] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/18/2018] [Indexed: 01/27/2023] Open
Abstract
Density functional theory calculations are used to investigate the detailed reaction mechanism of benzoylformate decarboxylase, a thiamin diphosphate (ThDP)-dependent enzyme that catalyzes the nonoxidative decarboxylation of benzoylformate yielding benzaldehyde and carbon dioxide. A large model of the active site is constructed on the basis of the X-ray structure, and it is used to characterize the involved intermediates and transition states and evaluate their energies. There is generally good agreement between the calculations and available experimental data. The roles of the various active site residues are discussed and the results are compared to mutagenesis experiments. Importantly, the calculations identify off-cycle intermediate species of the ThDP cofactor that can have implications on the kinetics of the reaction.
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Affiliation(s)
- Ferran Planas
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, Stockholm, Sweden
| | - Xiang Sheng
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, Stockholm, Sweden
| | - Michael J McLeish
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Fahmi Himo
- Arrhenius Laboratory, Department of Organic Chemistry, Stockholm University, Stockholm, Sweden
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Calixto AR, Ramos MJ, Fernandes PA. Influence of Frozen Residues on the Exploration of the PES of Enzyme Reaction Mechanisms. J Chem Theory Comput 2017; 13:5486-5495. [DOI: 10.1021/acs.jctc.7b00768] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Ana R. Calixto
- UCIBIO, REQUIMTE,
Departamento de Química
e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Maria J. Ramos
- UCIBIO, REQUIMTE,
Departamento de Química
e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Pedro A. Fernandes
- UCIBIO, REQUIMTE,
Departamento de Química
e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
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de Almeida Neves PAA, Silva EN, Beirão PSL. Microcalorimetric Study of Acetylcholine and Acetylthiocholine Hydrolysis by Acetylcholinesterase. ACTA ACUST UNITED AC 2017. [DOI: 10.4236/aer.2017.51001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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