Profiling the Cytochrome P450 2J2 Active Site.

Human cytochrome P450 2J2 (CYP2J2) is a membrane bound, heme-containing monooxygenase primary expressed in the heart. This enzyme oxidizes the double bonds in polyunsaturated fatty acids such as arachidonic acid and linoleic acid to epoxides, generating epoxyeicosatrienoic acids (EETs). Various EET products are implicated in cardioprotective effects, but also the promotion of cancer tumor growth and metastasis. Additionally, CYP2J2 can act on a range of pharmaceuticals. Thus, CYP2J2 is of clinical interest, but there is no structural information to understand how the CYP2J2 active site accommodates this wide variety of ligands. In this study, the CYP2J2 active site was defined by its ability to bind an array of >75 substrates, inhibitors, and xenobiotics, including a broad panel of azole compounds. The binding modes and affinities were determined by monitoring the shifts of the CYP2J2 heme Soret absorbance, which is indicative of heme environment perturbation. From these experiments the following spectral shift responses were observed: displacement of the heme-coordinated water (type-I binding mode), compound coordination to the heme iron (type-II), a red-shifted type-I binding mode, compound coordination to heme coordinated water (reverse type-I binding mode), or no spectral shift. As the latter result can be consistent with no binding or binding in the active site in a way that does not perturb the heme center, such compounds were investigated via a luminescence-based inhibition assay to verify their interaction with CYP2J2. As imidazole-containing ligands provide a fixed, known reference point for their interaction with the CYP2J2 heme iron, cheminformatics approaches were applied to these compounds to help provide insight into the chemical makeup of the CYP2J2 active site. The physical properties of these ligands were analyzed to identify key ligand features that drive CYP2J2 ligand preference. In the absence of protein structure information, this strategy provides a route to defining the CYP2J2 ligand binding site, potentially supporting the development of selective inhibitors that can help define the role of CYP2J2 modulation in vivo and potentially facilitate therapeutic strategies. © FASEB.

Citation

Nicole Motl, Richard D Smith, Heather A Carlson, Emily E Scott. Profiling the Cytochrome P450 2J2 Active Site. FASEB journal : official publication of the Federation of American Societies for Experimental Biology. 2022 May;36 Suppl 1

PMID: 35553025

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