Phosphoenol Pyruvate Carboxylase
(Orthophosphate: Oxaloacetate Carboxylase Phosphorylative EC 188.8.131.52)
This enzyme is involved in the fixation of carbon-dioxide in C4
plants. It has a high affinity to CO2
molecule. The reaction catalyzed by this enzyme is given below.
|Phosphoenol Pyruvate + CO2
Sorghum, maize, sugarcane etc. are some of C4
The oxaloacetic acid formed by the action of PEP case is coupled with MDH and followed by NADH oxidation. Since the sources of PEP case contain enough MDH there is no need to add MDH exogenously.
» Tris HCl Buffer 0.1M (pH
» Magnesium Chloride (10mM) 203.5mg/50mL water.
» Sodium Bicarbonate (10mM) 84mg/100mL water
» Phosphoenolpyruvate (5mM) 23.28mg/100mL water
» NADH (0.4mM) 5.32mg/10mL water
» Enzyme extract - see under MDH
1. Mix various recipes as shown below:
||Tris-HCl buffer pH 7.8
2. Proceed steps 2 to 4 as in MDH
Calculate as for MDH
1. Ting I P and Osmond, C B (1973) Plant Physiol 51
2. Sadasivam, S and Gowri, G (1981) Photosynthetica 15