title: Inhibition of spinach phosphoribulokinase by DL-glyceraldehyde.
abstract: Spinach chloroplast phosphoribulokinase is inhibited by DL-glyceraldehyde. The inhibition is non-competitive with respect to ribulose 5-phosphate (Ki 19mM) and ATP (Ki 20mM). The inhibition is discussed in relation to a previously reported inhibition of CO2 assimilation in intact and envelope-free chloroplasts by DL-glyceraldehyde. It is concluded that the inhibition of phosphoribulokinase is insufficient to account for the inhibition, by DL-glyceraldehyde, of O2 evolution with ribose 5-phosphate as substrate and that a further site of inhibition is also present in this system.
mesh_terms: D000255:Adenosine Triphosphate; D002245:Carbon Dioxide; D002736:Chloroplasts / Q000201:enzymology; D005985:Glyceraldehyde / Q000494:pharmacology*; D010100:Oxygen; D010770:Phosphotransferases / Q000037:antagonists & inhibitors*; D010944:Plants / Q000201:enzymology*; D012274:Ribulosephosphates
chemical_list: D012274:Ribulosephosphates; D002245:Carbon Dioxide; D005985:Glyceraldehyde; D000255:Adenosine Triphosphate; D010770:Phosphotransferases; D010100:Oxygen