title: Docosahexaenoic and eicosapentaenoic acids segregate differently between raft and nonraft domains.
abstract: Omega-3 polyunsaturated fatty acids (n-3 PUFA), enriched in fish oils, are increasingly recognized to have potential benefits for treating many human afflictions. Despite the importance of PUFA, their molecular mechanism of action remains unclear. One emerging hypothesis is that phospholipids containing n-3 PUFA acyl chains modify the structure and composition of membrane rafts, thus affecting cell signaling. In this study the two major n-3 PUFA found in fish oils, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, are compared. Using solid-state (2)H NMR spectroscopy we explored the molecular organization of 1-[(2)H(31)]palmitoyl-2-eicosapentaenoylphosphatidylcholine (PEPC-d(31)) and 1-[(2)H(31)]palmitoyl-2-docosahexaenoylphosphatidylcholine (PDPC-d(31)) in mixtures with sphingomyelin (SM) and cholesterol (chol). Our results indicate that whereas both PEPC-d(31) and PDPC-d(31) can accumulate into SM-rich/chol-rich raftlike domains, the tendency for DHA to incorporate into rafts is more than twice as great as for EPA. We propose that DHA may be the more bioactive component of fish oil that serves to disrupt lipid raft domain organization. This mechanism represents an evolution in the view of how PUFA remodel membrane architecture.
authors.affiliation: Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, USA.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Williams
authors.forename: Shawn E
authors.initials: SE
authors.lastname: Batten
authors.forename: Mitchel
authors.initials: M
authors.lastname: Harris
authors.forename: Benjamin Drew
authors.initials: BD
authors.lastname: Rockett
authors.forename: Saame Raza
authors.initials: SR
authors.lastname: Shaikh
authors.forename: William
authors.initials: W
authors.lastname: Stillwell
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Wassall
mesh_terms: D002784:Cholesterol / Q000737:chemistry; D003902:Detergents; D004281:Docosahexaenoic Acids / Q000737:chemistry*; D015118:Eicosapentaenoic Acid / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D021962:Membrane Microdomains / Q000737:chemistry*; D008567:Membranes, Artificial; D009829:Oleic Acids / Q000737:chemistry; D010713:Phosphatidylcholines / Q000737:chemistry; D013109:Sphingomyelins / Q000737:chemistry; D013696:Temperature
chemical_list: C434585:1-palmitoyl-2-elaidoylphosphatidylcholine; D003902:Detergents; D008567:Membranes, Artificial; D009829:Oleic Acids; D010713:Phosphatidylcholines; D013109:Sphingomyelins; D004281:Docosahexaenoic Acids; C033037:1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine; D002784:Cholesterol; D015118:Eicosapentaenoic Acid; C028694:1-palmitoyl-2-oleoylphosphatidylcholine