TY - JOUR
T1 - Evidence for a two proton dependent redox equilibrium in an archaeal Rieske iron-sulfur cluster
AU - Anemüller, Stefan
AU - Schmidt, Christian L.
AU - Schäfer, Günter
AU - Bill, Eckart
AU - Trautwein, Alfred X.
AU - Teixeira, Miguel
PY - 1994/7/15
Y1 - 1994/7/15
N2 - The recently detected Rieske iron - sulfur center in the membrane of the thermoacidophilic archaeon Sulfolobus acidocaldarius (Anemuller et al., 1993, FEBS Lett. 318, 61 - 64) was further characterized by EPR spectroscopy, coupled to redox - potentiometry and functional studies. The reduction potential is pH - dependent above pH 6, revealing the influence of two ionization equilibria in the oxidized form, with pKa ox - values of 6.2 and 8.5. Above pH 9, the slope of the curve is - 120 mV/pH - unit. A partially purified fraction exerted a ubiquinol - cytochrome c oxidoreductase activity. To our knowledge, for the first time, in a membrane bound Rieske iron - sulfur protein, unequivocal evidence for a two proton dependent redox equilibrium is presented.
AB - The recently detected Rieske iron - sulfur center in the membrane of the thermoacidophilic archaeon Sulfolobus acidocaldarius (Anemuller et al., 1993, FEBS Lett. 318, 61 - 64) was further characterized by EPR spectroscopy, coupled to redox - potentiometry and functional studies. The reduction potential is pH - dependent above pH 6, revealing the influence of two ionization equilibria in the oxidized form, with pKa ox - values of 6.2 and 8.5. Above pH 9, the slope of the curve is - 120 mV/pH - unit. A partially purified fraction exerted a ubiquinol - cytochrome c oxidoreductase activity. To our knowledge, for the first time, in a membrane bound Rieske iron - sulfur protein, unequivocal evidence for a two proton dependent redox equilibrium is presented.
UR - http://www.scopus.com/inward/record.url?scp=0028026972&partnerID=8YFLogxK
U2 - 10.1006/bbrc.1994.1920
DO - 10.1006/bbrc.1994.1920
M3 - Journal articles
AN - SCOPUS:0028026972
SN - 0006-291X
VL - 202
SP - 252
EP - 257
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -
