Reconciliation of opposing views on membrane-sugar interactions

Heidi Delcomyn Andersen, Chunhua Wang, Lise Arleth, Günther H.J. Peters, Peter Westh

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Abstract

It is well established that small sugars exert different types of stabilization of biomembranes both in vivo and in vitro. However, the essential question of whether sugars are bound to or expelled from membrane surfaces, i.e., the sign and size of the free energy of the interaction, remains unresolved, and this prevents a molecular understanding of the stabilizing mechanism. We have used small-angle neutron scattering and thermodynamic measurements to show that sugars may be either bound or expelled depending on the concentration of sugar. At low concentration, small sugars bind quite strongly to a lipid bilayer, and the accumulation of sugar at the interface makes the membrane thinner and laterally expanded. Above ∼0.2 M the sugars gradually become expelled from the membrane surface, and this repulsive mode of interaction counteracts membrane thinning. The dual nature of sugar–membrane interactions offers a reconciliation of conflicting views in earlier reports on sugar-induced modulations of membrane properties.
OriginalsprogEngelsk
TidsskriftProceedings of the National Academy of Science of the United States of America
Vol/bind108
Udgave nummer5
Sider (fra-til)1874-1878
ISSN0027-8424
DOI
StatusUdgivet - 2011

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