2 H NMR of oriented phospholipid/cholesterol bilayers containing an amphiphilic peptide

Publication date: Available online 18 January 2020Source: Biochimica et Biophysica Acta (BBA) - BiomembranesAuthor(s): Miranda L. Schmidt, James H. DavisAbstractLipid bilayers form the basis of cell membranes and the phase behaviour of the membrane has been linked to proper cell function. Model membranes composed of relatively simple mixtures of phospholipids and cholesterol can already exhibit complex phase behaviour. Specifically, liquid ordered–liquid disordered fluid phase coexistence occurs in mixtures which contain one saturated long chain phospholipid and one unsaturated long chain phospholipid and cholesterol. This fluid-fluid two phase region persists over a broad range of temperatures and sample compositions and can be observed experimentally in various sample preparations including multilamellar dispersions, bicelles, and multi-lamellae stacked on glass slides. In order to explore the practicality of using oriented samples with different concentrations of the peptide, we investigated the effect of the addition of a synthetic 22 residue amphiphilic peptide on the orientability and phase behaviour of the lipid mixtures, as well as the orientation and dynamics of the peptide itself via 2H NMR. Increasing the peptide concentration promoted the formation of the liquid ordered phase, suggesting a peferential interaction of the peptide with the thicker ordered phase. However, higher peptide content (> 4 mol %) had a significant negative effect on the alignment of bice...
Source: Biochimica et Biophysica Acta (BBA) Biomembranes - Category: Biochemistry Source Type: research