Raman spectroscopic study of the interactions of dimyristoyl- and 1-palmitoyl-2-oleoylphosphatidylcholine liposomes with myelin proteolipid apoprotein

Lateral diffusion of lipids in complex biological membranes.

“…Finally, it explains why the slopes of ln D vs. l/AF curves differ for different phospholipids with the same headgroup-'y is expected to be sensitive to the effects of chain-length differences on trans-gauche isomerization and van der Waals interactions between chains. In the discussion that follows on the effects of polypeptides and proteins on lateral diffusion, we will assume that a value of 0.25 for y, which reproduces experimental data on monolayer systems (11,12) (15,16) show no change in lipid C-H stretching region spectra, which reflect both acyl chain trans-gauche isomerization and chain packing (17) when peptides or proteins are incorporated into liquid crystalline-lipid bilayers well above the phase-transition temperature. Although this assumption is probably not universally valid, the theory allows effects of proteins on membrane area to be separated from their direct effects on diffusion.…”

Effects of membrane bilayer reorganizations on the 2103 cm−1 Raman spectral CD stretching mode linewidths in dimyristoyl phosphatidylcholine‐d54 (DMPC‐d54) liposomes

“…[1][2][3][4] Since multicomponent systems often exhibit congested vibrational patterns in the spectral intervals of most interest, the use of appropriately deuterated phospholipids has become widespread as a means of simplifying the problems inherent in severely overlapped band…”

“…During the past several years, both infrared and Raman spectroscopic techniques have amply demonstrated their potential for characterizing conformational reorganizations within the hydrophobic regions of intact biological membranes and related model systems. [1][2][3][4] Since multicomponent systems often exhibit congested vibrational patterns in the spectral intervals of most interest, the use of appropriately deuterated phospholipids has become widespread as a means of simplifying the problems inherent in severely overlapped band…”

SERS nano-imaging probes for characterizing extracellular surfaces

“…[25][26][27] The SERS spectrum of DPPC shows major peaks at 717 cm -1 (choline C-N stretch), 874 cm -1 , 890 cm -1 , 1063 cm -1 (acyl chain trans C-C stretch), 1130 cm -1 (trans C-C stretch), 1296 cm -1 (acyl chain CH 2 twist), and 1437 cm -1 , 2840 cm -1 (CH 2 symmetric stretch), 2878 cm -1 (CH 2 symmetric stretch), 2902 cm -1 , 2933 cm -1 (CH 3 symmetric stretch). [25][26][27][28] The SERS spectrum of sphingomyelin shows major bands at 717cm -1 (C-N stretch), 1060cm -1 (trans C-C stretch), 1125 cm -1 (trans C-C stretch), 1296 cm -1 (acyl chain CH 2 twist), 1434 cm -1 (not assigned), 2842 cm -1 (CH 2 symmetric stretch), 2876 cm -1 , 2900 cm -1 , and 2902 cm -1 . [25][26][27][28] While many of the bands for the different lipids are found at similar Raman shifts (1296 cm -1 ), there are several slight difference that can be distinguished as well as relative differences in the intensities of these Raman bands, allowing ratiometric analyses of multiple SERS bands to be used to distinguish between the components.…”

“…[25][26][27][28] The SERS spectrum of sphingomyelin shows major bands at 717cm -1 (C-N stretch), 1060cm -1 (trans C-C stretch), 1125 cm -1 (trans C-C stretch), 1296 cm -1 (acyl chain CH 2 twist), 1434 cm -1 (not assigned), 2842 cm -1 (CH 2 symmetric stretch), 2876 cm -1 , 2900 cm -1 , and 2902 cm -1 . [25][26][27][28] While many of the bands for the different lipids are found at similar Raman shifts (1296 cm -1 ), there are several slight difference that can be distinguished as well as relative differences in the intensities of these Raman bands, allowing ratiometric analyses of multiple SERS bands to be used to distinguish between the components. With these initial lipid characterization studies performed, as well as optimization of the probe for biological analyses, future studies will involve obtaining dynamic images of particular extracellular membrane components.…”