| Abstract: | The effect of phosphate, sulfate and other inorganic ions on the activity of phosphoenolpyruvate carboxylase (PEPC) from the C4 plant Cynodon dactylon were investigated for the first time, as well as their interaction with Clc-6-P, AMP and ma-late. Activation of PEPC by phosphate and sulfate ions was demonstrated and it was not dependent on the accompanying cations, something that was not clarified for PEPCs from other plant sources. No activation of this enzyme was observed by nitrate. PEPC activation was found to be competitive with glucoses-phosphate (Clc-6-P) and AMP stimulation and less sensitive to malate inhibition. This work showed that PEPC from C4plants could exhibit similar activation properties with the enzyme from CAM plants and different activation properties in plants of the same type, rendering the study of this enzyme from different plant sources necessary. |
