Paramagnetic Hydrophilic Probes in NMR Investigations of Membrane Systems

摘要: The ability of paramagnetic ions to shift or broaden NMR signals has been widely used for more than 15 years in organic chemistry and biochemistry studies single molecules. (For a book on this subject, see La Mar et al., 1973). In 1970 we attempted apply the investigation multimolecular phospholipid aggregates that serve as models biological membranes (Bergelson al, 1970; Bystrov 1971). Even our first experiments gave some spectacular results. these salts manganese various lanthanides were added sonicated aqueous dispersions egg yolk lecithin consisting single-shelled vesicles (sonicated liposomes), resonances methylene trimethylammonium protons before after addition compared. comparison showed signal (CH2)n groups hardly be affected by ions, whereas N(CH3)3 changed dramatically. case latter rise two components: one broadened becoming lost baseline other narrow, whose integral intensity was approximately 0.4 times shown initial sample (Fig. 1). This effect explained assuming only from outward-facing is Mn2+, residual peak belonging molecules located inner surface bilayer, which are not accessible metal.