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Updated: Jun 19, 2026
11:55
Examining the Conformational Dynamics of Membrane Proteins in situ with Site-directed Fluorescence Labeling
Published on: May 29, 2011
Molecular basis for the electric field modulation of cytochrome C structure and function
Pablo M De Biase1, Damián Alvarez Paggi, Fabio Doctorovich
1Departamento de Química Inorgánica, Analítica, y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, INQUIMAE-CONICET, Ciudad Universitaria, Pab. 2, C1428EHA, Buenos Aires, Argentina.
Journal of the American Chemical Society
|November 6, 2009
Summary
Electric fields alter cytochrome c (Cyt) structure, causing Met80 detachment and a shift from electron transfer to peroxidase activity. This conformational change impacts mitochondrial function and apoptosis.
Area of Science:
- Biochemistry
- Biophysics
- Computational Biology
Background:
- Cytochrome c (Cyt) is a crucial heme protein involved in mitochondrial electron transport and apoptosis.
- Its hexacoordinated heme structure is essential for its function as an electron shuttle.
Purpose of the Study:
- To investigate the structural and functional effects of electric fields on Cytochrome c.
- To elucidate the atomistic mechanisms behind electric-field-induced conformational changes in Cyt.
Main Methods:
- Molecular dynamics simulations were employed to model Cytochrome c in the presence of electric fields.
- Analysis focused on heme coordination, protein segment mobility, and energetic/entropic contributions.
Main Results:
- Biologically relevant electric fields induced increased mobility and structural distortion in Cyt.
- The sixth axial ligand, Met80, detached from the heme iron, leading to a pentacoordinated high-spin heme.
- This transition significantly lowered the reduction potential and increased peroxidase activity.
Conclusions:
- Electric fields can induce a conformational transition in Cytochrome c, switching its function.
- This switch may modulate electron transfer in mitochondria and initiate peroxidase activity in apoptosis.
- The findings provide an atomistic basis for interpreting experimental results on Cyt behavior.
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