Tethered Lipid Membrane Formation on Assemblies with Controlled Presentation of Anchor Molecules: A QCM-D Study
(English)Manuscript (preprint) (Other academic)
We have recently described a binary self-assembled monolayer (SAM) platform for studies of tethered bilayer lipid membrane (tBLM) formation using surface analysis techniques (Lee et al). Namely, this type of mixed SAMs consisted of a matrix molecule, HS-(CH2)15-CONHCH2CH2OH, and an anchor molecule, HS-(CH2)15-CONH-(CH2CH2O)6-CH2CONH-X, where X is -(CD2)7CD3 or -(CD2)15CD3. In the present work, we have employed quartz crystal microbalance with dissipation monitoring (QCM-D) to study in more detail small unilamellar vesicle (SUV) fusion on such SAMs formed from solutions with a range of mole fractions of the anchor. Using the QCM frequency and dissipation signals we were able to relate tBLM formation to the density of surface anchors. The QCM-D analysis revealed a critical SUV concentration on the surface is necessary for vesicle rupture and bilayer formation. We found that the critical SUV concentration decreased with increasing density of anchoring groups. Dissipation signal indicated the most pronounced release of water enclosed by the SUVs (related to vesicle rupturing) for the SAMs formed in the range of mole fractions between 1 and 10%. Also, we observed only minute differences in the behavior of the SUVs on SAMs terminated with -(CD2)7CD3 or -(CD2)15CD3 anchors, respectively.
suported lipid membrane, tethered bilayer lipid membrane, self-assembled monolayers, quartz crystal microbalance
IdentifiersURN: urn:nbn:se:liu:diva-77053OAI: oai:DiVA.org:liu-77053DiVA: diva2:524727