Small angle scattering reveals the orientation of cytochrome P450 19A1 in lipoprotein nanodiscs

• Published in: Journal of inorganic biochemistry 2024-08, Vol.257 (C), p.112579, Article 112579
• Main Authors: Hackett, John C., Krueger, Susan, Urban, Volker S., Zárate-Pérez, Francisco
• Format: Article
• Language: English
• Subjects: Aromatase - chemistry; Aromatase - metabolism; Cytochrome P450; Humans; Lipoproteins - chemistry; Lipoproteins - metabolism; Membrane protein; Molecular Dynamics Simulation; Nanodisc; Nanostructures - chemistry; SANS; SAXS; Scattering, Small Angle; X-Ray Diffraction
• ISSN: 0162-0134; 1873-3344; 1873-3344
• DOI: 10.1016/j.jinorgbio.2024.112579

Human aromatase (CYP19A1), the cytochrome P450 enzyme responsible for conversion of androgens to estrogens, was incorporated into lipoprotein nanodiscs (NDs) and interrogated by small angle X-ray and neutron scattering (SAXS/SANS). CYP19A1 was associated with the surface and centered at the edge of the long axis of the ND membrane. In the absence of the N-terminal anchor, the amphipathic A'- and G'-helices were predominately buried in the lipid head groups, with the possibly that their hydrophobic side chains protrude into the hydrophobic, aliphatic tails. The prediction is like that for CYP3A4 based on SAXS employing a similar modeling approach. The orientation of CYP19A1 in a ND is consistent with our previous predictions based on molecular dynamics simulations and lends additional credibility to the notion that CYP19A1 captures substrates from the membrane. Simultaneous fitting of small angle scattering data to a hybrid structural model of a human aromatase-nanodisc complex provides insight into the nature of the protein-membrane interaction. [Display omitted] •Aromatase nanodiscs were characterized by small angle x-ray and neutron scattering (SAXS/SANS).•A hybrid structural model of an aromatase nanodisc was derived from SAXS and SANS.•The orientation consistent with a substrate recognition at the membrane interface.