The effect of dolychols on the permeability barrier properties of lipid bilayers to alcaline cations

D. BOSCOBOINIK; M. FELIZ; E.A. DISALVO ; E. BELOCOPITOU

CHEMISTRY AND PHYSICS OF LIPIDS

ELSEVIER IRELAND LTD

Lugar: Amsterdam; Año: 1985 vol. 38 p. 343 - 352

0009-3084

The permeability of liposomes to water, glucose, Ca2+ and alkalinecations was monitored by recording the change in absorbance at 450 nm using a rapid reaction stopped-flow spectrophotometer. Liposomes were prepared with egg phosphatidylcholine and concentrations of dolichol ranging from 0.1% to 9% (w/w). Net permeability of phosphatidylcholine bilayers to alkalinecations was induced by the incorporation of dolichol. This effect was not observed in the case of non-charged solutes like glucose or in that of alkaline earth cations such as calcium. Permeation of K+ was significantly increased above the phase transition temperature. These results suggest that dolichols may play a role in biological membranes, besides the well-known glycosyl carrier function in the biosynthesis of glycoproteins.