Figure 2.

Activities of the mutants. A, Western blot of mitochondrial proteins extracted from transfected COS-1 cells, probed with anti-P450scc antiserum. B, Michaelis-Menten analysis. P450scc fusion constructs for WT-F2, Leu141Trp-F2, Phe215Ser-F2, Ala269Val-F2, Val415Glu, and c.835delA were transfected into COS-1 cells for 24 hours and incubated with 0.3μM, 1μM, 3μM, and 5μM 22R-hydroxycholesterol for 24 hours. Pregnenolone production in the culture media was measured by ELISA. The data are shown as mean ± SD. Analyses were not done for Val415Glu and 835delA, because their activities were below the sensitivity of the assay.