stigmatellin and 2-iodo-6-isopropyl-3-methyl-2--4-4--trinitrodiphenyl-ether

Stigmatellin and DNP-INT are effective inhibitors of the catalytic activity of the plastoquinol-plastocyanin oxidoreductase complex (cytochrome b6-f complex). Both inhibitors alter the EPR spectrum of the Rieske iron-sulfur center but do not produce band-shifts of cytochrome b-563. The midpoint redox potential of the Rieske center is unaffected by either inhibitor, although both alter the DBMIB-induced g-value shifts of the Rieske center. The results are considered in terms of binding domains for inhibitors in the cytochrome b6-f complex.

Topics: Binding Sites; Chloroplasts; Cytochrome b Group; Cytochrome b6f Complex; Electron Spin Resonance Spectroscopy; Iron-Sulfur Proteins; Metalloproteins; Nitrobenzenes; Oxidation-Reduction; Polyenes; Trinitrobenzenes