Article Figures & Data
Figures
- Fig. 1.
Time-dependent inactivation of CYP2C8 by 100 μM amiodarone (A), 100 μM clopidogrel acyl-β-D-glucuronide (B), 100 μM gemfibrozil 1-O-β-glucuronide (C), and 100 μM phenelzine (D) in HLMs, Bactosomes, EasyCYP Bactosomes, and Supersome lots 5057003 and 7053001. Each point represents the mean ± S.D. of quadruplicate incubations.
- Fig. 2.
The initial inactivation constants (kobs) (minute−1) of 100 μM amiodarone (AMD), 100 μM clopidogrel acyl-β-d-glucuronide (CAG), 100 μM gemfibrozil 1-O-β-glucuronide (GFG), 100 μM phenelzine (PHZ), and 1 μM raloxifene (RLX) in different enzyme sources.
- Fig. 3.
Residual CYP2C8 activity after preincubating 100 μM clopidogrel acyl-β-d-glucuronide for 0 and 30 minutes in Supersome lots 03459, 3221713, 5057003, and 7053001 with and without BSA. Each bar represents the mean ± S.D. of quadruplicate incubations.
- Fig. 4.
Depletion of 100 μM clopidogrel acyl-β-d-glucuronide (A) and 100 μM gemfibrozil 1-O-β-glucuronide (B) in HLMs and Supersomes with and without saccharolactone. Each point represents the mean ± S.D. of triplicate incubations.
- Fig. 5.
Time and concentration-dependent inactivation of CYP2C8 by clopidogrel acyl-β-d-glucuronide in Supersome lot 3221713 (A) and low reductase Bactosomes (B) and respective kobs vs. concentration plot (C). Each point represents the mean ± S.D. of quadruplicate incubations.
- Fig. 6.
The difference in absorbance (B) between the peak (Amax) and trough (Amin) observed with increasing concentrations of clopidogrel acyl-β-glucuronide, using CYP2C8 Bactosomes (A) and two different lots of CYP2C8 Supersomes (B and C). The data were transformed to plot the absorbance difference as a function of the ratio of the absorbance difference and substrate concentration (D–F). Once linearity was determined, the original plots were fitted to a hyperbolic function to determine the apparent spectral dissociation rate constants (Ks) of clopidogrel acyl-β-glucuronide to CYP2C8 enzyme systems.
Tables
- TABLE 1
Concentrations of CYP2C8 and other constituents in preincubations in the different enzyme preparations
Microsomal Protein CYP2C8 Cytochrome b5 Cytochrome b5/CYP2C8 Cytochrome c Reductase Activity fu, 100 μM Clopidogrel Acyl-β-d-Glucuronide mg/ml pmol/ml pmol/ml nmol/min HLMs, lot 38290 0.50 13.45a 260.00 19.33a 27.00 0.95 Bactosomes, lot C2C8BLR001 0.50 315.40 1591.67 5.05 16.00 0.90 Bactosomes with control protein 0.50 50.67 254.67 5.03 2.69 ND EasyCYP Bactosomes, lot C2C8BLR002 0.50 50.00 250.00 5.00 2.10 0.90 Supersomes, lot 03459 0.50 161.50 340.00 2.11 23.00 0.91 Supersomes, lot 3221713 0.50 63.50 150.00 2.36 7.20 0.92 Supersomes, lot 3221713 + BSA 0.50 63.50 150.00 2.36 7.20 0.83 Supersomes, lot 5057003 0.50 64.00 95.00 1.48 7.00 ND Supersomes, lot 7053001 0.50 143.00 210.00 1.47 23.00 0.91 Supersomes, lot 7053001 + BSA 0.50 143.00 210.00 1.47 23.00 0.86 fu, fraction unbound; ND, not defined.
↵a CYP2C8 abundance based on average CYP2C8 protein amount in HLMs (Kawakami et al., 2011; Gröer et al., 2014).
Data Supplement
- Supplemental Data -
2 supplemental tables, 2 figures, and references.
- Supplemental Data -
