Fig. 8From: Use of the KlADH3 promoter for the quantitative production of the murine PDE5A isoforms in the yeast Kluyveromyces lactis Biochemical properties of the purified 3XFlagPDE5A1 protein. a Eadie-Hofstee representation plot of cGMP hydrolysis. b Sildenafil inhibition curve. c Native PAGE gel shift by pre-incubation of 3XFlagPDE5A1 with Sildenafil. The purified 3XFlagPDE5A1 protein (1 μg) was incubated for 15′ at 30 °C with the inhibitor, fractioned on gel and stained with CoomassieBack to article page