Exploring the evolutionary route of the acquisition of betaine aldehyde dehydrogenase activity by plant ALDH10 enzymes: implications for the synthesis of the osmoprotectant glycine betaine

Table 1 Steady-state kinetic parameters of wild-type and mutant So BADH enzymes in the oxidation of BAL

Initial velocities were obtained at 30°C in 50 mM HEPES-KOH buffer, pH 8.0, containing 0.1 mM EDTA. In the experiments with variable BAL, the fixed concentration of NAD⁺ was 0.2 mM, and in the experiments with variable NAD⁺ the fixed BAL concentrations were at least 10-times their appK_m values estimated for each enzyme at fixed 0.2 mM NAD⁺. The apparent kinetic parameters were estimated by non-linear regression fit of the experimental data to the Michaelis-Menten equation. The values given in the Table are the mean ± standard deviation of the kinetic parameters estimated in two duplicate saturation experiments performed with enzymes from two different purification batches. Values for k_cat are expressed per subunit.

ISSN: 1471-2229