简介:Mixed distearoylphosphatidylethanolamine (DSPE) and dioleoylphosphatidylethanolamine (DOPE)
monolayers and bilayers have been deposited on mica using the Langmuir-Blodgett (LB) technique, as
amodel systemfor biomembran简介:Mixed distearoylphosphatidylethanolamine (DSPE) and dioleoylphosphatidylethanolamine (DOPE)
monolayers and bilayers have been deposited on mica using the Langmuir-Blodgett (LB) technique, as
amodel systemfor biomembranes. Investigation with atomic forcemicroscopy revealed phase-separation
for both monolayers in air and bilayers in water in the form of microscopic DSPE domains embedded in
a DOPE matrix. For the monolayers in air, the step height measured between the higher DSPE phase
and the lowerDOPE phasewas larger than expected fromthemolecular lengths, and a significant contrast
in adhesion and frictionwas observed despite identical lipid end groups. This unexpected behavior resulted
primarily froma difference in the filmmechanical properties, theDOPEphase being inelastically deformed
by the probe. For the bilayers in water, similar trends were found in terms of height, adhesion, and
friction, but an additional short-range repulsive hydration/steric force over the DSPE phase contributed
to the observed differences.详细>