Structure of a model lipid membrane oxidized by human 15-lipoxygenase-2.

Autor: Nemri J; Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, 1420 Austin Bluffs Pwky, Colorado Springs, CO, 80918, USA. Electronic address: jnemri@uccs.edu., Morales C; Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, 1420 Austin Bluffs Pwky, Colorado Springs, CO, 80918, USA. Electronic address: cmorale4@uccs.edu., Gilbert NC; Department of Biological Sciences, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA, 70803, USA. Electronic address: ngilbert@lsu.edu., Majewski J; Division of Molecular and Cellular Biosciences, National Science Foundation, Alexandria, VA, USA; Theoretical Biology and Biophysics at Los Alamos National Laboratory, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA; Department of Chemical and Biological Engineering and Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM, 87131, USA. Electronic address: jmajewsk@nsf.gov., Newcomer ME; Department of Biological Sciences, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA, 70803, USA. Electronic address: newcomer@lsu.edu., Vander Zanden CM; Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, 1420 Austin Bluffs Pwky, Colorado Springs, CO, 80918, USA. Electronic address: cvanderz@uccs.edu.
Jazyk: angličtina
Zdroj: Biochemical and biophysical research communications [Biochem Biophys Res Commun] 2024 Dec 10; Vol. 737, pp. 150533. Date of Electronic Publication: 2024 Aug 08.
DOI: 10.1016/j.bbrc.2024.150533
Abstrakt: Enzyme-mediated lipid oxidation is an important regulatory event in cell signaling, with oxidized lipids being potent signaling molecules that can illicit dramatic changes in cell behavior. For example, peroxidation of an arachidonoyl poly-unsaturated fatty acid by the human enzyme 15-lipoxygenase-2 (15-LOX-2) has been associated with formation of atherosclerotic plaques. Previous work on synthetically oxidized membranes has shown that oxidized lipid tails will change their conformation to facilitate interactions between the peroxide group and the lipid headgroups. However, this phenomenon has not been directly observed for a lipid membrane that has undergone enzyme-catalyzed oxidation. In this study, we report on the structure of a model lipid membrane before and after oxidation by 15-LOX-2. A model lipid membrane monolayer at the air-liquid interface was constructed from 1-stearoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (SAPC) in a Langmuir trough, and X-ray reflectivity measurements were conducted to determine the electron density profile of the system. Exposure to 15-LOX-2 caused a dramatic change in the SAPC structure, namely a blurred distinction between the lipid tail/head layers and shortening of the average lipid tail length by ∼3 Å. The electron density profile of the oxidized SAPC monolayer is similar to that of a synthetically oxidized substrate mimic. Overall, this reported observation of an enzymatically-oxidized membrane structure in situ is helping to bridge a gap in the literature between structural studies on synthetically oxidized membranes and cellular studies aiming to understand physiological responses.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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