Immunologically cross-reactive and redox-competent cytochrome b6/f-complexes in the chlorophyll-free plasma membrane of cyanobacteria.
Plasma and thylakoid membranes were separated and purified from cell-free extracts of the cyanobacteria Anacystis nidulans, Synechocystis 6714, Anabaena variabilis and Nostoc sp. strain Mac. Immunoblots of the membrane proteins using antisera raised against subunits I-IV of the chloroplast b6/f-complex gave evidence for the presence of a homologous complex in both plasma and thylakoid membranes from the four species of cyanobacteria investigated. Both plasma and thylakoid membranes catalyzed the electron transfer from (exogenous) plastoquinol-9 and NADH to horse heart ferricytochrome c. However, while with plasma membranes these reactions were severely inhibited by low concentrations of antimycin A and rotenone, respectively, the inhibitors were without major effect on thylakoid membranes. The results will be discussed in terms of a possible similarity (analogy and/or homology?) of cyanobacterial plasma membranes to the inner mitochondrial membrane.
Kraushaar
H
H
Biophysical Chemistry Group, Institute of Physical Chemistry, University of Vienna, Austria.
Hager
S
S
Wastyn
M
M
Peschek
G A
GA
D002462:Cell Membrane / Q000378:metabolism; D002734:Chlorophyll / Q000302:isolation & purification; D003429:Cross Reactions; D000458:Cyanobacteria / Q000378:metabolism*; D003580:Cytochromes / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D045348:Cytochromes f; D004579:Electron Transport; D007700:Kinetics; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D013045:Species Specificity
D003580:Cytochromes; D009243:NAD; D002734:Chlorophyll; D045348:Cytochromes f