Probing iso-1-cytochrome c structure by site-directed spin labeling and electron paramagnetic resonance techniques

• Authors: Janusz Pyka , Artur Osyczka , Bohdan Turyna , Wojciech Blicharski , Wojciech Froncisz
• Languages of publication: EN

Abstracts

EN

A cysteine-specific methanethiosulfonate spin label was introduced into yeast iso-1-cytochrome c at three different positions. The modified forms of cytochrome c included: the wild-type protein labeled at naturally occurring C102, and two mutated proteins, S47C and L85C, labeled at positions 47 and 85, respectively (both S47C and L85C derived from the protein in which C102 had been replaced by threonine). All three spin-labeled protein derivatives were characterized using electron paramagnetic resonance (EPR) techniques. The continuous wave (CW) EPR spectrum of spin label attached to L85C differed from those recorded for spin label attached to C102 or S47C, indicating that spin label at position 85 was more immobilized and exhibited more complex tumbling than spin label at two other positions. The temperature dependence of the CW EPR spectra and CW EPR power saturation revealed further differences of spin-labeled L85C. The results were discussed in terms of application of the site-directed spin labeling technique in probing the local dynamic structure of iso-1-cytochrome c.

Keywords

EN

iso-1-cytochrome c; Saccharomyces cerevisiae; site-directed mutagenesis; spin label; electron paramagnetic resonance

• Publisher: Polish Biochemical Society
• Journal: Acta Biochimica Polonica
• Year: 1999
• Volume: 46
• Issue: 4
• Pages: 889-899

Dates

published

1999

received

1999-10-06

Contributors

author

Janusz Pyka

• Department of Biophysics, Institute of Molecular Biology, Jagiellonian University, Al. A. Mickiewicza 3, 31-120 Kraków, Poland

author

Artur Osyczka

• Department of Biophysics, Institute of Molecular Biology, Jagiellonian University, Al. A. Mickiewicza 3, 31-120 Kraków, Poland

author

Bohdan Turyna

• Department of Biophysics, Institute of Molecular Biology, Jagiellonian University, Al. A. Mickiewicza 3, 31-120 Kraków, Poland

author

Wojciech Blicharski

• Department of Biophysics, Institute of Molecular Biology, Jagiellonian University, Al. A. Mickiewicza 3, 31-120 Kraków, Poland

author

Wojciech Froncisz

• Department of Biophysics, Institute of Molecular Biology, Jagiellonian University, Al. A. Mickiewicza 3, 31-120 Kraków, Poland