Cholesterol Effects on the Physical Properties of Lipid Membranes Viewed by Solid-state NMR Spectroscopy

Trivikram R. Molugu, Michael F Brown

Research output: Contribution to journalArticle

2 Scopus citations

Abstract

In this chapter, we review the physical properties of lipid/cholesterol mixtures involving studies of model membranes using solid-state NMR spectroscopy. The approach allows one to quantify the average membrane structure, fluctuations, and elastic deformation upon cholesterol interaction. Emphasis is placed on understanding the membrane structural deformation and emergent fluctuations at an atomistic level. Lineshape measurements using solid-state NMR spectroscopy give equilibrium structural properties, while relaxation time measurements study the molecular dynamics over a wide timescale range. The equilibrium properties of glycerophospholipids, sphingolipids, and their binary and tertiary mixtures with cholesterol are accessible. Nonideal mixing of cholesterol with other lipids explains the occurrence of liquid-ordered domains. The entropic loss upon addition of cholesterol to sphingolipids is less than for glycerophospholipids, and may drive formation of lipid rafts. The functional dependence of 2H NMR spin-lattice relaxation (R 1Z) rates on segmental order parameters (S CD) for lipid membranes is indicative of emergent viscoelastic properties. Addition of cholesterol shows stiffening of the bilayer relative to the pure lipids and this effect is diminished for lanosterol. Opposite influences of cholesterol and detergents on collective dynamics and elasticity at an atomistic scale can potentially affect lipid raft formation in cellular membranes.

Original languageEnglish (US)
Pages (from-to)99-133
Number of pages35
JournalAdvances in Experimental Medicine and Biology
Volume1115
DOIs
Publication statusPublished - Jan 1 2019

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Keywords

  • Area per lipid
  • Cholesterol
  • Lanosterol
  • Lipid rafts
  • Membrane elasticity
  • Solid-state NMR

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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