Semianaerobic

To remove the broad signal arising from the magnetic coupling of the semiquinone to the high spin Fe 2+, the iron was biochemically replaced with diamagnetic Zn 2+ according to the procedures outlined by Utschig et al. 19 Argon gas was slowly blown over the samples to achieve semianaerobic conditions, after which 10 mM dithionite was added to generate SQ A .