Phosphoglycerate as a Hill Oxidant in a Reconstituted Chloroplast System

The ability of intact chloroplasts to evolve oxygen when illuminated in the presence of 3-phosphoglycerate is lost following osmotic shock but may be largely restored by the addition of ATP, catalytic amount of nicotinamide adenine dinucleotide phosphate, ferredoxin, and a soluble fraction derived from chloroplasts. In the presence of uncoupling agents and ATP, the rate is faster than that supported by intact chloroplasts. In the absence of uncoupling agents, the ATP requirement may be partially met by photophosphorylation.