Figure 4From: Steroid biotransformations in biphasic systems with Yarrowia lipolytica expressing human liver cytochrome P450 genesInfluence of copy number and type of reductase on CYP activity. CYP2D6 (A) and CYP3A4 (B) activity of and CPR activities of Y. lipolytica single-copy and multicopy transformants. Strains coexpressed under pICL1-control the codon-optimized P450 2D6syn (A) or P450 3A4syn (B) in combination with the wild-type human or Y. lipolytica NADPH-P450 reductases (hCPRwt, YlCPR) from integrated single-copies or multiple vector copies as indicated, except the control strain YL23 on the left in A and B, containing only one endogenous chromosomal YlCPR copy, which is present as background in all strains. Cultivation at 28°C in YNBG on glucose, induction by 1% ethanol, microsomes isolation, whole-cell CYP activity and cytochrome P450 reductase (CPR) activity (determined as NADPH-cytochrome c reductase, NCR) measurements were performed as described in Materials and Methods. Filled bars, CPR activity; hatched bars, CYP activities; -, no genes; + genes in single copy; ++ genes in multicopy.Back to article page