TY - JOUR
T1 - Time-resolved resonance raman investigation of cytochrome oxidase catalysis
T2 - Observation of a new oxygen-isotope sensitive Raman band
AU - Ogura, Takashi
AU - Takahashi, Satoshi
AU - Shinzawa-Itoh, Kyoko
AU - Yoshikawa, Shinya
AU - Kitagawa, Teizo
N1 - Publisher Copyright:
© 1991 The Chemical Society of Japan.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 1991/10
Y1 - 1991/10
N2 - The reduction of dioxygen by cytochrome oxidase has been investigated, in the time interval between 0.1 and 5.4 ms after initiation of the reaction, by using time-resolved resonance Raman spectroscopy combined with the Artificial Cardiovascular System [Ogura et al., Biochemistry, 28, 8022 (1989)]. At 0.5 ms we observed a new oxygen-isotope sensitive Raman band at 356 cm-1 for 16O2, which shifted down to 341 cm-1 for 18O2. The temporal behavior of this band was found to be very close to that of another oxygen-isotope sensitive band at 788 cm-1 which had been assigned previously to the Fe(IV)=0 stretching mode of the ferryloxo intermediate [Ogura et al., J. Biol. Chem., 265, 14721(1990)]. However, the fact that the 788 cm"1 band shifts to a higher frequency (802 cm"1) in 2H20, taken together with the present detection of two oxygen-isotope sensitive bands, prompts us to suggest an alternative assignment; namely, that these bands arise from the O--O- (788 cm-1) and Fe(III)-O- (356 cm-1) stretching modes of the Fe(III)-O--0--H intermediate. This conclusion forces a reconsideration of the currently accepted view of cytochrome oxidase catalysis.
AB - The reduction of dioxygen by cytochrome oxidase has been investigated, in the time interval between 0.1 and 5.4 ms after initiation of the reaction, by using time-resolved resonance Raman spectroscopy combined with the Artificial Cardiovascular System [Ogura et al., Biochemistry, 28, 8022 (1989)]. At 0.5 ms we observed a new oxygen-isotope sensitive Raman band at 356 cm-1 for 16O2, which shifted down to 341 cm-1 for 18O2. The temporal behavior of this band was found to be very close to that of another oxygen-isotope sensitive band at 788 cm-1 which had been assigned previously to the Fe(IV)=0 stretching mode of the ferryloxo intermediate [Ogura et al., J. Biol. Chem., 265, 14721(1990)]. However, the fact that the 788 cm"1 band shifts to a higher frequency (802 cm"1) in 2H20, taken together with the present detection of two oxygen-isotope sensitive bands, prompts us to suggest an alternative assignment; namely, that these bands arise from the O--O- (788 cm-1) and Fe(III)-O- (356 cm-1) stretching modes of the Fe(III)-O--0--H intermediate. This conclusion forces a reconsideration of the currently accepted view of cytochrome oxidase catalysis.
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U2 - 10.1246/bcsj.64.2901
DO - 10.1246/bcsj.64.2901
M3 - Article
AN - SCOPUS:85023498412
VL - 64
SP - 2901
EP - 2907
JO - Bulletin of the Chemical Society of Japan
JF - Bulletin of the Chemical Society of Japan
SN - 0009-2673
IS - 10
ER -