Figure 2.

Inactivation of HMG-CoA reductase enzyme by lovastatin. Microsomes (100 μg) prepared from subconfluent cultures of MDA-MB-157 were incubated at 37°C in the presence of the indicated concentrations of lovastatin, pro-drug, or pravastatin followed by the addition of ¹⁴C-HMG-CoA. After the lactonization of the reaction with HCL, the samples were resolved by TLC and analyzed by PhosphorImaging. The activity of HMG-CoA reductase is a measure of the percent conversion of ¹⁴C-HMG-CoA into mevalolactone, the end product of the HMG-CoA reductase. ●, lovastatin mixture; ○, pro-drug; ■, pravastatin.