The conformation of the polar group of lysophosphatidylcholine in H2O; conformational changes induced by polyvalent cations

摘要: The conformation of the polar group egg lysophosphatidylcholine and 1-myristoyl-sn-glycero-3-phosphorylcholine present as micelles in aqueous solution has been studied using NMR methods. In absence polyvalent cations preferred derived from spin-spin coupling constants is similar, but not identical, to that phosphatidylethanolamine crystal structure (cf. Hitchcock, P.B., Mason, R., Thomas, K.M. Shipley, G.G. (1974) Proc. Natl. Acad. Sci. U.S. 71, 3036–3040). presence lanthanides induces a conformational change involving primarily phosphorylcholine group, e.g. torsion angle α5 changes an all gauche approximate trans disposition. → transitions observed with angles α3 produce more extended orientation (relative hydrocarbon chain axis). very similar diacyl phosphatidylcholines fully hydrated bilayers Hauser, H., Phillips, M.C., Levine, B.A. Williams, R.J.P. (1976) Nature 261, 390–394) P-N vector at about 45° bilayer.