TY - JOUR
T1 - Effect of ATP on the redox cycle of respiratory chain-linked DPNH dehydrogenase and the localization of coupling site I
AU - Gutman, M.
AU - Mayr, M.
AU - Oltzik, R.
AU - Singer, T. P.
N1 - Funding Information:
This study was supported by grants from the National Science Foundation (GB 8248) and the American
PY - 1970/10/9
Y1 - 1970/10/9
N2 - On adding DPNH to a phosphorylating membrane preparation in the presence of O2 the reduction of a chromophore, which has been tentatively identified as nonheme iron of DPNH dehydrogenase, may be observed by dual wavelength spectrophotometry at 470-500 mμ. With rotenone or piericidin present a part of the chromophore remains permanently bleached even after exhaustion of the DPNH. ATP, however, causes rapid and complete reoxidation of the chromophore. This effect is abolished by oligomycin and dinitrophenol. Control experiments show that under these conditions the rotenone block between DPNH dehydrogenase and cytochrome b is substantially complete. Analysis of the data suggest that coupling site I is located between the specific binding site of rotenone and the nonheme irons responsible for the g=1.94 signal, both of which appear to be constituents of DPNH dehydrogenase.
AB - On adding DPNH to a phosphorylating membrane preparation in the presence of O2 the reduction of a chromophore, which has been tentatively identified as nonheme iron of DPNH dehydrogenase, may be observed by dual wavelength spectrophotometry at 470-500 mμ. With rotenone or piericidin present a part of the chromophore remains permanently bleached even after exhaustion of the DPNH. ATP, however, causes rapid and complete reoxidation of the chromophore. This effect is abolished by oligomycin and dinitrophenol. Control experiments show that under these conditions the rotenone block between DPNH dehydrogenase and cytochrome b is substantially complete. Analysis of the data suggest that coupling site I is located between the specific binding site of rotenone and the nonheme irons responsible for the g=1.94 signal, both of which appear to be constituents of DPNH dehydrogenase.
UR - http://www.scopus.com/inward/record.url?scp=0014938377&partnerID=8YFLogxK
U2 - 10.1016/0006-291X(70)90465-1
DO - 10.1016/0006-291X(70)90465-1
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AN - SCOPUS:0014938377
SN - 0006-291X
VL - 41
SP - 40
EP - 44
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -