All-atom molecular dynamics simulation studies of fully hydrated gel phase DPPG and DPPE bilayers

Structural characterization of phosphatidylglycerol model membranes containing the antibiotic target lipid II molecule: a Raman microspectroscopy study

“…The peak fitting procedure applied to the spectral range comprised between 1000 and 1150 cm −1 reveals also the presence of several overlapped bands attributable to the υ s PO 2 − and υC―O modes of the lipids polar headgroups (see Figs and ). The assignment of these features is based on reported experimental values for PG and PC model membranes in different phase states; quantum chemical calculations for the charged molecule [CH 3 ―O―P(O) 2 ―O―CH 2 ―CHOH―CH 2 OH] − that mimics the PG moiety; and MD simulations of pure PG membranes in liquid crystalline and gel states . Predicted wavenumbers for the hydroxyl C―O bonds and the υ s PO 2 − mode are listed in Table .…”

“…a) are assigned to the υ s PO 2 − vibration. According to the MD simulations, this charged group shows a high tendency to form intermolecular H‐bond associations with water molecules and/or with glycerol OH groups of adjacent lipids in addition to the intramolecular H‐bonds with glycerol hydroxyls; the presence of Na + ions also contributes to reduce the interlipid charge‐charge repulsion . In order to connect the structural insights provided by the MD simulations with the vibrational behavior experimentally observed by Raman spectroscopy, we performed quantum‐chemical calculations for the model molecule in different conformations, both in free state and in the presence of one or two H‐bonded water molecules, and with or without Na + ions.…”

Complexation of cationic polyelectrolyte with anionic phospholipid vesicles: Concentration, molecular weight and salt effects

“…The positive zeta potential clearly indicates charge reversal of the vesicles, which can occur with sufficient polycation binding. Since the charge spacing of PDADMAC (0.55 nm) is close to 0.45-0.6 nm between the charges of two neighboring lipid molecules in the vesicles [43,52], the observed charge reversal arises primarily from entropic gain of PDADMAC chains, where only a portion of charges of each chain bind to the lipid molecules. The overcompensation reinstates the electrostatic repulsion between bilayers or between lipids, as mentioned earlier.…”

Phase Behavior of Lipid Bilayers: A Dissipative Particle Dynamics Simulation Study

“…Actually, the tilted arrangement of the tail chains probably intimates two different phases: the tilted sub-gel phase L c or the tilted gel phase L β . [64,65] Further try has been done to find more proofs to distinguish this case from the sub-gel state. At a hh = 25 and T* = 0.1, the packing mode of lipid can be confirmed as hexagonal ordering because of the positions of the first four peaks corresponding to 1 : √ 3 : 2 : √ 7 (as shown in Figure 5) which indicates the packing pattern shown as insert of Figure 5.…”