Abstract
The reactions of [spinach] chloroplast thylakoid lamellae with the chemical probe p-(diazonium-) benzenesulfonic acid (DABS) in the light were reinvestigated. In contrast to a previous report, electron transport from a photosystem I electron donor to methylviologen was inhibited by this treatment. During the incubation of chloroplasts with DABS in the light, the probe is altered with high rates. Under aerobic conditions, a concomitant O2 uptake is observed, which is stoichiometric to the amount of DABS altered. Under anaerobic conditions, the binding of the 35S-labeled probe to the membranes in the light is stimulated 2-3 fold as compared to the binding under aerobic conditions. The photoreduction of the probe rather than a conformational change of the membrane may be at least partially responsible for the increased reagent binding observed in the light.

This publication has 0 references indexed in Scilit: