Investigation of Cytochrome P450 2J2 Ligand Binding Modes

Abstract

Human cytochrome P450 2J2 (CYP2J2) plays a multifaceted role in cardioprotection and xenobiotic metabolism. CYP2J2 oxidizes endogenous polyunsaturated fatty acids P450s, including arachidonic acid and linoleic acid, to various epoxyeicosatrienoic acids (EETs). These EETs are implicated in vasodilation and protection against hypoxia‐reperfusion, but also promote tumor growth and metastasis, where inhibition may be a clinical advantage. Recently, it has been reported that CYP2J2 is inhibited by anti‐hypertensive drugs including manidipine, azelnidipine, and telmisartan. In its drug metabolism role, CYP2J2 metabolizes numerous xenobiotics including anti‐histamine and anti‐cancer agents. While kinetic and metabolic parameters for many of these endogenous and xenobiotic compounds have been reported, it remains to be elucidated how such a wide variety of ligands are accommodated by the CYP2J2 active site. This study determined the binding modes of a catalog of CYP2J2 ligands, including substrates, inhibitors, xenobiotics, and a broad panel of azole containing compounds for the purpose of better understanding their interactions with CYP2J2. The binding modes and affinities were determined by monitoring the spectral shift of the P450 heme Soret absorbance, which is indicative of perturbation of the heme environment. Such spectral shift indicated varying responses: displacement of the heme‐coordinated water (a type‐I binding mode), compound coordination to the heme iron (a type‐II binding mode), or no spectral shift. As the latter result can be consistent with no binding or a binding in the active site in a way that does not perturb the heme center, these latter compounds were investigated via a luminescence‐based inhibition assay to verify their interaction with CYP2J2. Overall, this study aides in improving our understating of different ligand scaffolds that are compatible with CYP2J2 binding to support the development of therapeutics and inhibitors of CYP2J2.Support or Funding InformationNational Institutes of Health Grant R37 GM076343