Difference in subcellular distribution between 45-and 37-kDa mevalonate pyrophosphate decarboxylase in rat liver

We previously reported that the CP diet (a diet containing 5% cholestyramin e and 0.1% pravastatin)-induced new species of 37-kDa mevalonate pyrophosph ate decarboxylase (MPD) was characteristically and immunologically very sim ilar to the well-known 45-kDa MPD. In the present study, we found a differe nce in subcellular distribution between 45- and 37-kDa MPD by cell fraction ation and immunoblot analysis. The cytosol fraction contained 45- and 37-kD a MPD. Peroxisomal fraction contained a small amount of 45-kDa MPD, but not 37-kDa MPD. Also, 45-kDa MPD in peroxisome is localized in the matrix. Fro m these data, the difference in subcellular distribution between 45- and 37 -kDa MPD may be due to differences in the physiological role of cholesterol biosynthesis in rat liver.