Inhibition of photophosphorylation and electron transport by N,N-dimethylformamide.

The basal electron transport of pea chloroplasts was inhibited by 78% by 7% (v/v) N,N-dimethylformamide; the inhibition was partially reversed by NH4Cl. N,N-Dimethylformamide also inhibited the Pi-ATP exchange, ATP synthesis and to a smaller extent Mg2+-ATPase activity. Light induced proton uptake was not affected by up to 30% (v/v) N,N-dimethylformamide. Uncoupled electron transport in photosystem II was inhibited to a larger extent by N,N-dimethylformamide than in photosystem I. These results indicate that N,N-dimethylformamide acts as an inhibitor of energy transfer and electron transport.