Figure 2.

Steroid bioconversions with cell-free extract (CFE) of E. coli C43(DE3) (pIT2cyp154C5) (pACYCcamAB) employing different CYP154C5 concentrations. CFE reactions with different concentrations of progesterone (3) and testosterone (5) were performed in 50 mM potassium phosphate buffer pH 7.4 at 30°C for 24 h. Sodium formate (150 mM) and formate dehydrogenase from Candida boidinii (FDH, 0.5 U/mL) were used for cofactor regeneration (NADH, 50 μM). Substrates were added as stock solutions in 36% w/v hydroxypropyl-β-cyclodextrin in water.