No abstract

1‐Palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine (POPC), an unsaturated acyl chain containing lipid, is often the predominant lipid in eukaryotic cell membranes in which it is crucial for the fluidity of membranes under physiological conditions. Commercially available, partially deuterated [D31]1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine ([D31]POPC) does not provide sufficient isotopic contrast for detailed structural studies of multicomponent membranes through neutron techniques. Herein, a relatively straightforward and generic chemical deuteration method is discussed for the asymmetric synthesis of perdeuterated [D31]1‐palmitoyl‐[D33]2‐oleoyl‐sn‐[D5]glycero‐[D13]3‐phosphocholine ([D82]POPC) that also allows selective deuteration of any of its constituent groups. Neutron reflectivity of a [D82]POPC‐supported bilayer was used to experimentally determine the neutron scattering length density profile of the lipid. The acyl chains of [D82]POPC are closely contrast‐matched to heavy water, whereas the very high scattering length density of the deuterated glycerophosphocholine head groups provides good contrast to membrane‐binding agents in both deuterated and non‐deuterated solvent environments.

No abstract

An understanding of the location of peptides, proteins, and other biomolecules within the bicontinuous cubic phase is crucial for understanding and evolving biological and biomedical applications of these hybrid biomolecule-lipid materials, including during in meso crystallization and drug delivery. While theoretical modeling has indicated that proteins and additive lipids might phase separate locally and adopt a preferred location in the cubic phase, this has never been experimentally confirmed. We have demonstrated that perfectly contrast-matched cubic phases in D2O can be studied using small-angle neutron scattering by mixing fully deuterated and hydrogenated lipid at an appropriate ratio. The model transmembrane peptide WALP21 showed no preferential location in the membrane of the diamond cubic phase of phytanoyl monoethanolamide and was not incorporated in the gyroid cubic phase. While deuteration had a small effect on the phase behavior of the cubic phase forming lipids, the changes did not significantly affect our results.

Replacing all protons on a polymer by deuterium has a dramatic impact on spin-dependent properties of the material in devices.