Figure 6.

Stability analysis of recombinant human G6PD variants. (A) Thermal stability of G6PD variants. Changes in the CD signal at 222 nm were monitored as the temperature increased from 20 °C to 80 °C. The T_m (melting temperature midpoint of the transition values) was calculated for each variant. (B) Stability analysis of G6PD variants in the presence of guanidine hydrochloride (Gdn-HCl). All enzymes were incubated at 0.2 mg/mL in 50 mM phosphate buffer pH 7.35 in the presence of the indicated concentrations of Gdn-HCl for 2 h at 37 °C and subsequently the enzymatic activity was measured. Residual activity was expressed as a percentage of the activity for the same sample measured at 25 °C without Gdn-HCl and were diluted immediately before use. The experiments were performed in triplicate and the standard errors were less than 4%.