Modulation of the domain topography of biphasic monolayers of stearic acid and dimyristoyl phosphatidylcholine

F. VEGA MERCADO, B. MAGGIO Y N. WILKE.

CHEMISTRY AND PHYSICS OF LIPIDS

ELSEVIER IRELAND LTD

Lugar: Amsterdam; Año: 2012 vol. 165 p. 232 - 237

0009-3084

The phase diagram of mixed monolayers composed of dimyristoyl phosphatidylcholine (DMPC) andstearic acid (SA) on different subphases was previously reported. It was observed that on acid subphases,liquid-condensed domains with shapes that depend on the SA proportion are formed. For mixtures with40–45 mole% of SA, the domain shape changes from flower-like to circular domains. In this work, wecarried out a detailed study of the driving force for the shape change. We find that it is related to thedomain density which, in turn, is driven by the domain nucleation process and thus by oversaturationof the system leading to phase segregation. This could be a way of self-regulating the local electrostaticsand mechanical properties in membrane surfaces with segregated phase domains.