Quantification of CYP3A4 protein in liver samples

CYP3A4 protein levels in 154 liver samples were measured using the capillary western blotting Jess system as described (Collins and Wang, 2021b). Briefly, total tissue lysates were prepared (Collins and Wang, 2021b) and a mouse anti-CYP3A4 antibody (R&D MAB 9079, 1:20 dilution) and NIR-conjugated anti-mouse secondary antibody (Biotechne, San Jose, CA, United States, 1:20 dilution) were used for detection. The total protein loaded in each lane was measured using the total protein channel in the Jess system. CYP3A4 protein (pmol) per mg total protein was calculated from a standard curve generated from a purified GST-fusion CYP3A4 protein (FisherScientific) measured on the Jess system. After log10 transformation, CYP3A4 protein levels followed a normal distribution as previously described (Collins and Wang, 2021b).