A comparison of the effect of one and two mono-unsaturated acyl chains on the structure of phospholipid bilayers: a high pressure infrared spectroscopic study

Hydration and Lyotropic Melting of Amphiphilic Molecules: A Thermodynamic Study Using Humidity Titration Calorimetry

“…chains into a paraffin-like structure (31). The gel-like character of the solid lipid is reflected in the wavenumber of the as (CH 2 ) band which is shifted by ϳ2.5 cm Ϫ1 to larger values when compared with that of crystalline DTAB (Fig.…”

“…The effective shift of the as (CH 2 ) band in the fluid and gel states of lipids depends on the balance between repulsive and attractive contributions to the intermolecular potential and on the conformation of the hydrocarbon chain, i.e., on u CH-CH and on u intra , respectively (50). Measurements at increasing hydrostatic pressure have shown that the wavenumber of the CH 2 stretching bands decreases at pressures up to ϳ0.5 GPa but increases at higher pressures (31). Attractive or repulsive interactions seem to dominate the respective compression ranges.…”

Pressure effect on the bilayer phase transition of asymmetric lipids with an unsaturated acyl chain

“…The examination of pressure effects on the gel to liquid‐crystalline phase transition of phospholipid bilayer membranes is of particular interest to studies of pressure reversal of anesthesia, pressure adaptation in deep‐sea organisms, and high‐pressure sterilization in food processing. Although bilayer membranes composed of phosphatidylcholines (PCs) containing two identical linear saturated fatty acyl chains have been the most thoroughly studied membrane configurations under high pressure, there have been few studies on the phase properties of unsaturated PC bilayers under high pressure 6–13 . Siminovitch et al .…”

“…Siminovitch et al . also measured infrared spectra of palmitoyl‐oleoyl‐PC (POPC) and oleoyl‐palmitoyl‐PC (OPPC) bilayer membranes at 28° C as a function of pressure up to 4700 MPa, in order to compare the effect of one and two monounsaturated (oleoyl) chains on the structure and packing of phospholipid bilayers 9 . Winter and Pilgrim have reported by small‐angle neutron scattering under high pressure up to 200 MPa that the effect of two trans double bonds in DEPC and a cis double bond in the sn ‐2 chain of POPC enhances the conformational disorder in the hydrocarbon chains not only in the liquid crystalline phase, but also in the gel state 10 .…”

Effect of cholesterol on structural and dynamic properties of tripalmitoyl glyceride. A high-pressure infrared spectroscopic study

“…In our laboratory in Ottawa, we have made extensive use of vibrational spectroscopy under high pressure to gain new insights into the physical properties of biomembranes and model membrane systems (Auger et al, 1987(Auger et al, , 1988Siminovitch et al, 1988;Wong, 1984Wong, , 1986Wong, , 1987aWong et al, 1988;Wong and Mantsch, 1988a and b). Pressure is now well recognized as an essential variable.…”