Deciphering Melatonin-Stabilized Phase Separation in Phospholipid Bilayers

TitleDeciphering Melatonin-Stabilized Phase Separation in Phospholipid Bilayers
Publication TypeJournal Article
Year of Publication2019
AuthorsBolmatov, D., W. McClintic, G. Taylor, C. Stanley, C. Do, C. Collier, Z. Leonenko, M. Lavrentovich, and J. Katsaras
Start Page12236
Date Published08/2019

Lipid bilayers are fundamental building blocks of cell membranes, which contain the machinery needed to perform a range of biological functions, including cell–cell recognition, signal transduction, receptor trafficking, viral budding, and cell fusion. Importantly, many of these functions are thought to take place in the laterally phase-separated regions of the membrane, commonly known as lipid rafts. Here, we provide experimental evidence for the “stabilizing” effect of melatonin, a naturally occurring hormone produced by the brain’s pineal gland, on phase-separated model membranes mimicking the outer leaflet of plasma membranes. Specifically, we show that melatonin stabilizes the liquid-ordered/liquid-disordered phase coexistence over an extended range of temperatures. The melatonin-mediated stabilization effect is observed in both nanometer- and micrometer-sized liposomes using small angle neutron scattering (SANS), confocal fluorescence microscopy, and differential scanning calorimetry. To experimentally detect nanoscopic domains in 50 nm diameter phospholipid vesicles, we developed a model using the Landau–Brazovskii approach that may serve as a platform for detecting the existence of nanoscopic lateral heterogeneities in soft matter and biological materials with spherical and planar geometries.

Refereed DesignationRefereed