|
|
Study of the regulation of phosphoenolpyruvate carboxylase activity in higher plants
Škrletová, Denisa ; Ryšlavá, Helena (advisor) ; Müller, Karel (referee)
Phosphoenolpyruvate carboxylase (EC 4.1.1.31; PEPC) is one of the carbon dioxide- fixing enzymes, which yields oxaloacetate from phosphoenolpyruvate and bicarbonate. Regulation of PEPC activity occurs at many levels. In addition to pH and concentration of activators and inhibitors, it is phosphorylation as well. Phosphorylation of PEPC causes a change of kinetic parameters, such as maximal reaction rate, sensitivity to activation or inhibition. Considering that, there is still little information like this about C3 plants and that regulation is in various plant species different, I have dealt with monitoring of the kinetic parameters and regulation possibilities of PEPC isolated from C3 plant sources (Cannabis sativa L., Chenopodium quinoa, Pisum sativum L., Lens culinaris). While the activity of PEPC from leaves of Cannabis sativa L. was decreased by alkaline phosphatase, the activity of PEPC from seeds of Chenopodium quinoa, Pisum sativum L., Lens culinaris was not affected by alkaline phosphatase. The affinity of PEPC from seeds Chenopodium quinoa, Pisum sativum L., Lens culinaris to the substrate PEP was higher than in the case of PEPC from leaves of Cannabis sativa L.. For PEPC from Cannabis sativa L. was found that the apparent dephosphorylation leads to decrease of sensitivity to the...
|
guest ::
