Docosahexaenoic acid promotes micron scale liquid-ordered domains. A comparison study of docosahexaenoic versus oleic acid containing phosphatidylcholine in raft-like mixtures

Abstract

The understanding of the functional role of the lipid diversity in biological membranes is a major challenge. Lipid models have been developed to address this issue by using lipid mixtures generating liquid-ordered (Lo)/liquid-disordered (Ld) immiscibility. The present study examined mixtures comprising Egg sphingomyelin (SM), cholesterol (chol) and phosphatidylcholine (PC) either containing docosahexaenoic (PDPC) or oleic acid (POPC). The mixtures were examined in terms of their capability to induce phase separation at the micron- and nano-scales. Fluorescence microscopy, electron spin resonance (ESR), X-ray diffraction (XRD) and calorimetry methods were used to analyze the lateral organization of the mixtures. Fluorescence microscopy of giant vesicles could show that the temperature of the micron-scale Lo/Ld miscibility is higher for PDPC than for POPC ternary mixtures. At 37°C, no micron-scale Lo/Ld phase separation could be identified in the POPC containing mixtures while it was evident for PDPC. In contrast, a phase separation was distinguished for both PC mixtures by ESR and XRD, indicative that PDPC and POPC mixtures differed in micron vs nano domain organization. Compared to POPC, the higher line tension of the Lo domains observed in PDPC mixtures is assumed to result from the higher difference in Lo/Ld order parameter rather than hydrophobic mismatch.

Remodeling of the postsynaptic plasma membrane during neural development

“…, 1999), and domain formation (Shaikh et al. , 2004; Georgieva et al. , 2015), suggesting physical remodeling of synaptic membranes in neural development.…”

“…More indirectly, polyunsaturated lipids have also been implicated in enhancing raft stability (Shaikh et al. , 2004; Georgieva et al. , 2015), and we recently confirmed in model membranes and cultured mast cells (Levental et al.…”

“…Although polyunsaturated lipids are usually not raft components (Soni et al. , 2008), they can enhance raft formation by fluidizing nonraft regions, thereby increasing the propensity for domain separation (Wassall and Stillwell, 2008; Georgieva et al. , 2015; Levental et al.…”

Untangling Direct and Domain-Mediated Interactions Between Nicotinic Acetylcholine Receptors in DHA-Rich Membranes

“…One ω-3 in particular, Docosahexaenoic acid (DHA), is prevalent in the native neuromuscular membrane and is strongly associated with flexible and well-defined domains (Turk and Chapkin, 2013;Shaikh et al, 2004). Additionally, DHA is a major contributor to brain functioning, motor activity, and cardiac health; however, its specific effects on neuromuscular health are poorly understood (Lavandera et al, 2017;Wassall and Stillwell, 2008;Georgieva et al, 2015).…”

Preferential interaction of the Alzheimer peptide Aβ‐(1–42) with Omega‐3‐containing lipid bilayers: structure and interaction studies

“…A,C). No additional spectral component, evocative of domain formation , was detected. The rigidity of the membrane is only slightly reduced with respect to NML‐LB even in the presence of the higher amount of Omega‐3 lipids, as the S value is 0.68 for 5‐PCSL and 0.38 for 14‐PCSL.…”