Inhibition of Oxygen Evolution by Cacalol and Its Derivatives

Abstract

The inhibition of ATP synthesis, proton uptake and electron transport (basal, phosphorylating and uncoupled) from water to methylviologen indicates that cacalol and its derivatives act as electron transport inhibitors. Since on one hand photosystem I is not affected and electron transport from DPC to QA is midly affected and on the other hand the electron transport from water to DCIP, and water to silicomolibdate are inhibited, we conclude that the site of inhibition of cacalol is located at the oxygen evolution level. Cacalol derivatives inhibit electron flow between P680 to QA and probably also the QB site. © 1991, Walter de Gruyter. All rights reserved.