Critical fluctuations in domain-forming lipid mixtures

被引：364

作者：

Veatch, Sarah L.

Soubias, Olivier

Keller, Sarah L.

Gawrisch, Klaus ^{[1
]}

机构：

[1] NIAAA, NIH, Bethesda, MD 20892 USA

[2] Univ British Columbia, Dept Microbiol & Immunol, Vancouver, BC V6T 1Z4, Canada

[3] Univ Washington, Dept Chem, Seattle, WA 98195 USA

[4] Cornell Univ, Dept Chem & Chem Biol, Ithaca, NY 14853 USA

来源：

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA | 2007年 / 104卷 / 45期

关键词：

lipid rafts; liquid-immiscibility; NMR relaxation; phase diagram; critical behavior;

D O I：

10.1073/pnas.0703513104

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Critical fluctuations are investigated in lipid membranes near miscibility critical points in bilayers composed of dioleoylphosphatidylcholine, chain perdeuterated dipalmitoyl phosphatidylcholine, and cholesterol. Phase boundaries are mapped over the temperature range from 10 degrees C to 60 degrees C by deuterium NMR. Tie-lines and three-phase triangles are evaluated across two-phase and three-phase regions, respectively. In addition, a line of miscibility critical points is identified. NMR resonances are broadened in the vicinity of critical points, and broadening is attributed to increased transverse relaxation rates arising from modulation of chain order with correlation times on a microsecond time scale. We conclude that spectral broadening arises from composition fluctuations in the membrane plane with dimensions of < 50 nm and speculate that similar fluctuations are commonly found in cholesterol-containing membranes.

引用

页码：17650 / 17655

页数：6

共 40 条

[1] USE OF A FLUORESCENT CHOLESTEROL DERIVATIVE TO MEASURE LATERAL MOBILITY OF CHOLESTEROL IN MEMBRANES [J].