Human cytochrome C natural variants: Studying the membrane binding properties of G41S and Y48H by fluorescence energy transfer and molecular dynamics.
Int J Biol Macromol
; 274(Pt 1): 133371, 2024 Aug.
Article
em En
| MEDLINE
| ID: mdl-38914400
ABSTRACT
Cytochrome C (cyt C), the protein involved in oxidative phosphorylation, plays several other crucial roles necessary for both cell life and death. Studying natural variants of cyt C offers the possibility to better characterize the structure-to-function relationship that modulates the different activities of this protein. Naturally mutations in human cyt C (G41S and Y48H) occur in the protein central Ω-loop and cause thrombocytopenia 4. In this study, we have investigated the binding of such variants and of wild type (wt) cyt C to synthetic cardiolipin-containing vesicles. The mutants have a lower propensity in membrane binding, displaying higher dissociation constants with respect to the wt protein. Compressibility measurements reveal that both variants are more flexible than the wt, suggesting that the native central Ω-loop is important for the interaction with membranes. Such hypothesis is supported by molecular dynamics simulations. A minimal distance analysis indicates that in the presence of cardiolipin the central Ω-loop of the mutants is no more in contact with the membrane, as it happens instead in the case of wt cyt C. Such finding might provide a hint for the reduced membrane binding capacity of the variants and their enhanced peroxidase activity in vivo.
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Base de dados:
MEDLINE
Assunto principal:
Ligação Proteica
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Cardiolipinas
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Citocromos c
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Simulação de Dinâmica Molecular
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article