A non-radioisotopic anion-exchange chromatographic method to measure the CO2/O-2 specificity factor for ribulose bisphosphate carboxylase/oxygenase

A non-radioisotopic anion-exchange ion chromatographic method for measuring the carboxylation/oxygenation specificity (tau) of ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) is presented. The assay measures the amounts of fixation products at varying [CO2]/[O-2] ratios to measure the relative rates of CO2 and O-2 fixation reactions, The amount of 3-phosphoglycerate (3-PGA) and phosphoglycolate (PG) in the reaction mixture were measured with a conductivity detector and the specific factor was calculated using the following equations: v(c) = ([3-PGA] - [PG])/2 and v(0) = [PG]. By this method, specificity factors for RubisCOs were measured without using radioactive reagents.