The control of 3-phosphoglycerate reduction in isolated chloroplasts by the concentrations of ATP, ADP and 3-phosphoglycerate.
1. Oxygen evolution by reconstituted chloroplasts with 3-phosphoglycerate as substrate was inhibited by ADP. This inhibition was overcome by increased concentrations of 3-phosphoglycerate or by the addition of excess ATP. 2. The initial rate of 3-phosphoglycerate reduction by chloroplast stromal extracts, measured as 3-phosphoglycerate-dependent oxidation of NADPH, was also dependent on the concentrations of 3-phosphoglycerate, ADP and ATP. 3. Within the range of concentrations of 3-phosphoglycerate, ADP and ATP expected to occur within intact chloroplasts, the rate of 3-phosphoglycerate (PGA) reduction by stromal extract was proportional to the ratio [ATP] [PGA]/[ADP]. 4. These results are consistent with the notion that the substrates and products of 3-phosphoglycerate kinase control the rate of 3-phosphoglycerate reduction via a mass action effect.
D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism*; D005994:Glycerophosphates / Q000378:metabolism*; D007700:Kinetics; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects; D010944:Plants
D005994:Glycerophosphates; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D010100:Oxygen