Figure 2.

Measurement of pregnenolone synthesis by the STAR p.N148K mutant. (A) The pregnenolone synthesis by the STAR p.N148K mutant was compared with WT STAR after their expression in nonsteroidogenic COS-1 cells. (B) Quantitative analysis of the amount of steroid synthesized through phosphorimager analysis. Y-axis is presented in arbitrary units (AU) developed by phosphoimager program. (C and D), GC/MS analysis of the pregnenolone identified from the TLC plate, where panel (C) is the liquid chromatogram and (D) is the mass spectrometric identification of the steroid, pregnenolone. Data represented in panel B is the mean±s.e.m. of three independent experiments performed at three different times.