TY - JOUR
T1 - Melting-Temperature-Dependent Interactions of Ergosterol with Unsaturated and Saturated Lipids in Model Membranes
AU - Bui, Tham Thi
AU - Suga, Keishi
AU - Kuhl, Tonya L.
AU - Umakoshi, Hiroshi
N1 - Funding Information:
This work was primarily supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant-in-Aids for Scientific Research (A) (26249116), Grant-in-Aids for Young Scientists (B) (16K18279), Grant-in-Aids for Challenging Exploratory Research (T15K142040), and NSF chemistry division through grant CHE-1413745. T.T.B. is grateful for support from a Japanese Government (Monbukagakusho: MEXT) scholarship while completing this study. K.S. expresses his gratitude to the COSMETOLOGY Research Foundation and Multidisciplinary Research Laboratory System of Osaka University. T.L.K is grateful for support from the National Science Foundation chemistry division through grant CHE-1413745.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/8/13
Y1 - 2019/8/13
N2 - Sterols such as cholesterol (Chol) and ergosterol (Erg) are known to regulate membrane properties in higher eukaryotes and in lower eukaryotes, respectively. To better understand the modulation of membrane properties by Erg, binary lipid membranes composed of Erg and diacylglycerophosphocholine (PC) were studied in Langmuir monolayer and bilayer vesicle systems. From the excess area measured by pressure-Area isotherms, attractive interactions between Erg and saturated PC were significant above the melting temperature (Tm) of PC. Conversely, repulsive interactions were observed at temperatures below Tm. From the analyses of membrane fluidity and polarity using fluorescence probes, similar trends were observed for bilayer systems where Erg had an ordering effect on saturated PC vesicles in the fluid state. However, Chol had a stronger ordering effect than Erg. In unsaturated PC systems, Erg did not alter membrane ordering. These findings demonstrate that the interaction of Erg with the fluid-state PC lipids will maintain lower-eukaryote membranes in a more ordered state, similar to the effect of cholesterol in higher eukaryotes.
AB - Sterols such as cholesterol (Chol) and ergosterol (Erg) are known to regulate membrane properties in higher eukaryotes and in lower eukaryotes, respectively. To better understand the modulation of membrane properties by Erg, binary lipid membranes composed of Erg and diacylglycerophosphocholine (PC) were studied in Langmuir monolayer and bilayer vesicle systems. From the excess area measured by pressure-Area isotherms, attractive interactions between Erg and saturated PC were significant above the melting temperature (Tm) of PC. Conversely, repulsive interactions were observed at temperatures below Tm. From the analyses of membrane fluidity and polarity using fluorescence probes, similar trends were observed for bilayer systems where Erg had an ordering effect on saturated PC vesicles in the fluid state. However, Chol had a stronger ordering effect than Erg. In unsaturated PC systems, Erg did not alter membrane ordering. These findings demonstrate that the interaction of Erg with the fluid-state PC lipids will maintain lower-eukaryote membranes in a more ordered state, similar to the effect of cholesterol in higher eukaryotes.
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U2 - 10.1021/acs.langmuir.9b01538
DO - 10.1021/acs.langmuir.9b01538
M3 - Article
C2 - 31310548
AN - SCOPUS:85071265778
SN - 0743-7463
VL - 35
SP - 10640
EP - 10647
JO - Langmuir
JF - Langmuir
IS - 32
ER -