Structural and functional insights into lysine acetylation of cytochrome c using mimetic point mutants
| Autor: | Gonzalo Pérez-Mejías, José Luis Olloqui-Sariego, Inmaculada Márquez, Rafael Andreu, Alejandra Guerra-Castellano, Juan José Calvente, Irene Díaz-Moreno, Miguel A. De la Rosa |
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| Přispěvatelé: | Ministerio de Ciencia e Innovación (España), European Research Council, Universidad de Sevilla. Departamento de Química Física |
| Rok vydání: | 2021 |
| Předmět: |
QH301-705.5
Mutant Lysine Cytochrome c Cytochromes c1 Bioenergetics bioenergetics General Biochemistry Genetics and Molecular Biology Electron Transport Electron Transport Complex IV Structure-Activity Relationship Cytochrome C1 Cytochrome c oxidase Animals Humans post‐translational modifications Biology (General) Research Articles Binding Sites biology Cytochrome bc1 Chemistry electron transport chain Cytochromes c Acetylation Electron transport chain Kinetics cytochrome c Biochemistry Mutation biology.protein Thermodynamics Oxidation-Reduction Protein Processing Post-Translational Research Article Post-translational modifications |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname idUS. Depósito de Investigación de la Universidad de Sevilla FEBS Open Bio FEBS Open Bio, Vol 11, Iss 12, Pp 3304-3323 (2021) |
| Popis: | Post‐translational modifications frequently modulate protein functions. Lysine acetylation in particular plays a key role in interactions between respiratory cytochrome c and its metabolic partners. To date, in vivo acetylation of lysines at positions 8 and 53 has specifically been identified in mammalian cytochrome c, but little is known about the structural basis of acetylation‐induced functional changes. Here, we independently replaced these two residues in recombinant human cytochrome c with glutamine to mimic lysine acetylation and then characterized the structure and function of the resulting K8Q and K53Q mutants. We found that the physicochemical features were mostly unchanged in the two acetyl‐mimetic mutants, but their thermal stability was significantly altered. NMR chemical shift perturbations of the backbone amide resonances revealed local structural changes, and the thermodynamics and kinetics of electron transfer in mutants immobilized on gold electrodes showed an increase in both protein dynamics and solvent involvement in the redox process. We also observed that the K8Q (but not the K53Q) mutation slightly increased the binding affinity of cytochrome c to its physiological electron donor, cytochrome c 1—which is a component of mitochondrial complex III, or cytochrome bc 1—thus suggesting that Lys8 (but not Lys53) is located in the interaction area. Finally, the K8Q and K53Q mutants exhibited reduced efficiency as electron donors to complex IV, or cytochrome c oxidase. Acetylation is the main post‐translational modification of proteins in eukaryotic cells, affecting more than 60% of mitochondrial proteins. Mammalian cytochrome c, in particular, is found acetylated at lysines 8 and 53. Here, we characterize two acetyl‐mimetic mutants (Lys‐to‐Gln mutation) of human cytochrome c to gain insight into the structural and functional changes that could further explain the acetylation role in cancer and other diseases. |
| Databáze: | OpenAIRE |
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