NADPH-supported E1 hydroxylation activities of human CYP1A1 variants
. | 2-OH-Estrone . | . | . | 4-OH-Estrone . | . | . | 6α-OH-Estrone . | . | . | 15α-OH-Estrone . | . | . | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
. | Vmax . | Km . | Vmax/Km . | Vmax . | Km . | Vmax/Km . | Vmax . | Km . | Vmax/Km . | Vmax . | Km . | Vmax/Km . | ||||||||
CYP1A1.1 | 0.4 ± 0.03 | 12.2 ± 1.2 | 0.033 | 0.1 ± 0.03 | 22.6 ± 11.7 | 0.004 | 0.2 ± 0.1 | 86 ± 40 | 0.002 | 1.2 ± 0.1 | 85 ± 12 | 0.014 | ||||||||
CYP1A1.2 | 2.5 ± 0.3 | 6.3 ± 2.0 | 0.397 | 0.5 ± 0.1 | 12.7 ± 1.9 | 0.039 | 0.2 ± 0.02 | 27.3 ± 4.6 | 0.008 | 1.0 ± 0.1 | 20.5 ± 5.8 | 0.049 | ||||||||
CYP1A1.4 | 0.3 ± 0.03 | 13.1 ± 3.0 | 0.023 | 0.1 ± 0.03 | 24.4 ± 9.8 | 0.004 | 0.1 ± 0.04 | 45 ± 29 | 0.002 | 1.0 ± 0.2 | 46 ± 21 | 0.022 |
. | 2-OH-Estrone . | . | . | 4-OH-Estrone . | . | . | 6α-OH-Estrone . | . | . | 15α-OH-Estrone . | . | . | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
. | Vmax . | Km . | Vmax/Km . | Vmax . | Km . | Vmax/Km . | Vmax . | Km . | Vmax/Km . | Vmax . | Km . | Vmax/Km . | ||||||||
CYP1A1.1 | 0.4 ± 0.03 | 12.2 ± 1.2 | 0.033 | 0.1 ± 0.03 | 22.6 ± 11.7 | 0.004 | 0.2 ± 0.1 | 86 ± 40 | 0.002 | 1.2 ± 0.1 | 85 ± 12 | 0.014 | ||||||||
CYP1A1.2 | 2.5 ± 0.3 | 6.3 ± 2.0 | 0.397 | 0.5 ± 0.1 | 12.7 ± 1.9 | 0.039 | 0.2 ± 0.02 | 27.3 ± 4.6 | 0.008 | 1.0 ± 0.1 | 20.5 ± 5.8 | 0.049 | ||||||||
CYP1A1.4 | 0.3 ± 0.03 | 13.1 ± 3.0 | 0.023 | 0.1 ± 0.03 | 24.4 ± 9.8 | 0.004 | 0.1 ± 0.04 | 45 ± 29 | 0.002 | 1.0 ± 0.2 | 46 ± 21 | 0.022 |
NOTE: For conditions of experiments and analysis see legend of Table 1. Vmax data are given in picomoles of product per minute/picomoles of CYP1A1, Km data are in micromoles per liter, and catalytic efficiencies Vmax/Km are expressed in liter/micromoles per minute. Data represent mean ± SE as determined by nonlinear regression using software described under Materials and Methods.