Figure 2.

Displacement of tightly bound NADP⁺ by addition of glucose 6-phosphate. The purified G6PD enzyme, freed of any loosely bound NADP⁺ by serial dilution, was incubated at room temperature with glucose 6-phosphate at 1 mM (final concentration of 8.47 μM G6PD) for 30 min before passing down a Sephadex G-75 column pre-equilibrated and eluted with the 0.1 M Tris-HCl buffer at pH 7.6. The gel-filtration profile was monitored at 280 nm to locate the protein peak and at 340 nm to locate and quantitate the NADPH peak.