Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Vitamin E does not Disturb Polyunsaturated Fatty Acid Lipid Domains

Published

Author(s)

Mitchell DiPasquale, Michael H. Nguyen, Stuart R. Castillo, Isabelle J. Dib, Elizabeth Kelley, Drew Marquardt

Abstract

The antioxidant function of vitamin E in biomembranes remains a prominent topic of discussion. As its limitations as an antioxidant persist and novel functions are discovered, our understanding of the role of vitamin E becomes increasingly enigmatic. As a lipophilic molecule, vitamin E has been shown to influence the properties of its host membrane, and a wealth of research has connected vitamin E to polyunsaturated fatty acid (PUFA) lipids. Here, we use contrast-matched small angle neutron scattering and differential scanning calorimetry to integrate these fields by examining the influence of vitamin E on lipid domain stability in PUFA-based lipid mixtures. The influence of α-tocopherol, γ-tocopherol, and α-tocopherylquinone on the lateral organization of a 1:1 lipid mixture of saturated distearoylphosphatidylcholine (DSPC) and polyunsaturated palmitoyl-linoleoylphosphatidylcholine (PLiPC) with cholesterol provides a complement to our growing understanding of the influence of tocopherol on lipid phases. Characterization of domain melting suggests a slight depression in the transition temperature and a decrease in transition cooperativity, which are consistent with previous calorimetric studies. Tocopherol concentrations that are an order of magnitude higher than anticipated physiological concentrations (2 mole percent) do not significantly perturb lipid domains; however, addition of 10 mole percent is able to destabilize domains and promote lipid mixing. This observation is qualitatively consistent with our previous study based in a composition with macroscopic domains of high line tension. In contrast to this behaviour, increasing concentrations of the oxidized product of α-tocopherol, α-tocopherylquinone, induces a proportional increase in domain stabilization. We speculate how the contrasting effect of the oxidized product may supplement the antioxidant response of vitamin E.
Citation
Biochemistry
Volume
61
Issue
21

Keywords

vitamin E, tocopherol, polyunsaturated fatty acid (PUFA), domains, phase separation, small angle neutron scattering

Citation

DiPasquale, M. , Nguyen, M. , Castillo, S. , Dib, I. , Kelley, E. and Marquardt, D. (2022), Vitamin E does not Disturb Polyunsaturated Fatty Acid Lipid Domains, Biochemistry, [online], https://dx.doi.org/10.1021/acs.biochem.2c00405 (Accessed July 20, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created November 1, 2022, Updated January 23, 2024