TY - JOUR
T1 - Time-resolved single-turnover of ba3 oxidase from Thermus thermophilus
AU - Siletsky, Sergey A.
AU - Belevich, Ilya
AU - Jasaitis, Audrius
AU - Konstantinov, Alexander A.
AU - Wikström, Mårten
AU - Soulimane, Tewfik
AU - Verkhovsky, Michael I.
PY - 2007/12
Y1 - 2007/12
N2 - The kinetics of the oxidation of fully-reduced ba3 cytochrome c oxidase from Thermus thermophilus by oxygen were followed by time-resolved optical spectroscopy and electrometry. Four catalytic intermediates were resolved during this reaction. The chemical nature and the spectral properties of three intermediates (compounds A, P and O) reproduce the general features of aa3-type oxidases. However the F intermediate in ba3 oxidase has a spectrum identical to the P state. This indicates that the proton taken up during the P → F transition does not reside in the binuclear site but is rather transferred to the covalently cross-linked tyrosine near that site. The total charge translocation associated with the F → O transition in ba3 oxidase is close to that observed during the F → O transition in the aa3 oxidases. However, the PR → F transition is characterized by significantly lower charge translocation, which probably reflects the overall lower measured pumping efficiency during multiple turnovers.
AB - The kinetics of the oxidation of fully-reduced ba3 cytochrome c oxidase from Thermus thermophilus by oxygen were followed by time-resolved optical spectroscopy and electrometry. Four catalytic intermediates were resolved during this reaction. The chemical nature and the spectral properties of three intermediates (compounds A, P and O) reproduce the general features of aa3-type oxidases. However the F intermediate in ba3 oxidase has a spectrum identical to the P state. This indicates that the proton taken up during the P → F transition does not reside in the binuclear site but is rather transferred to the covalently cross-linked tyrosine near that site. The total charge translocation associated with the F → O transition in ba3 oxidase is close to that observed during the F → O transition in the aa3 oxidases. However, the PR → F transition is characterized by significantly lower charge translocation, which probably reflects the overall lower measured pumping efficiency during multiple turnovers.
KW - Catalytic cycle
KW - Cytochrome c oxidase
KW - Electric potential generation
KW - Electron transfer
KW - Thermus thermophilus
UR - http://www.scopus.com/inward/record.url?scp=36549060589&partnerID=8YFLogxK
U2 - 10.1016/j.bbabio.2007.09.010
DO - 10.1016/j.bbabio.2007.09.010
M3 - Article
C2 - 17964277
AN - SCOPUS:36549060589
SN - 0005-2728
VL - 1767
SP - 1383
EP - 1392
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
IS - 12
ER -