Development and qualification of recombinant Göttingen Minipig CYP3A22 and CYP3A29

In vitro drug metabolism assays are essential in early drug development to evaluate drug disposition. These assays often use hepatic subcellular fractions and recombinant enzymes originating from both human and nonclinical species. Within this domain, cytochrome P450 (CYP) 3A enzymes are considered key players for drug metabolism. Although recombinant CYP3A enzymes are available for several nonclinical species, isoform-specific enzymes from Göttingen Minipigs remain unavailable. Therefore, recombinant Göttingen Minipig CYP3A22 and CYP3A29 enzymes were developed in Escherichia coli . Their catalytic functionalities were examined using probe substrates (i.e., benzyl-oxy-methyl-resorufin and Luciferin-IPA), and clinically relevant human CYP3A4 substrates (i.e., midazolam and testosterone) along with known inhibitors (i.e., ketoconazole and troleandomycin). Gene sequence comparison to domestic pig revealed sequence variations for both r-CYP3A22 and r-CYP3A29. BOMR metabolism was detected in both constructs, but only r-CYP3A22 metabolized Luciferin-IPA. r-CYP3A22 exhibited a higher apparent affinity for midazolam, with a lower K m and comparable V max to r-CYP3A29, whereas r-CYP3A29 showed a greater maximal metabolic capacity toward testosterone, with a higher V max and similar K m as compared to r-CYP3A22. Ketoconazole exhibited potent reversible inhibitory effects on testosterone and midazolam metabolism in both enzymes. Troleandomycin strongly inhibited both constructs in a time-dependent manner; however, an IC 50 shift was only measurable for r-CYP3A22. These results provide important insights into Göttingen Minipig CYP3A isoform-specific functionality which are relevant for species selection in future nonclinical studies.