dioleoyl-phosphatidylethanolamine and 1-2-diphytanoylphosphatidylcholine

Liposomes are widely used as synthetic analogues of cell membranes and for drug delivery. Lipid-binding DNA nanostructures can modify the shape, porosity and reactivity of liposomes, mediated by cholesterol modifications. DNA nanostructures can also be designed to switch conformations by DNA strand displacement. However, the optimal conditions to facilitate stable, high-yield DNA-lipid binding while allowing controlled switching by strand displacement are not known. Here, we characterized the effect of cholesterol arrangement, DNA structure, buffer and lipid composition on DNA-lipid binding and strand displacement. We observed that binding was inhibited below pH 4, and above 200 mM NaCl or 40 mM MgCl2, was independent of lipid type, and increased with membrane cholesterol content. For simple motifs, binding yield was slightly higher for double-stranded DNA than single-stranded DNA. For larger DNA origami tiles, four to eight cholesterol modifications were optimal, while edge positions and longer spacers increased yield of lipid binding. Strand displacement achieved controlled removal of DNA tiles from membranes, but was inhibited by overhang domains, which are used to prevent cholesterol aggregation. These findings provide design guidelines for integrating strand displacement switching with lipid-binding DNA nanostructures. This paves the way for achieving dynamic control of membrane morphology, enabling broader applications in nanomedicine and biophysics.

Topics: Cholesterol; DNA; DNA, Single-Stranded; Hydrogen-Ion Concentration; Kinetics; Liposomes; Magnesium Chloride; Nanostructures; Nucleic Acid Conformation; Phosphatidylcholines; Phosphatidylethanolamines; Sodium Chloride; Solutions; Thermodynamics

The study of ion channel activity and the screening of possible inhibitor molecules require reliable methods for production of active channel proteins, their insertion into artificial membranes and for the measurement of their activity. Here we report on cell-free expression of soluble and active K

Topics: Elapid Venoms; Escherichia coli; Fluorescent Dyes; Gene Expression; Genetic Vectors; Humans; Isoxazoles; Kv1.1 Potassium Channel; Kv1.3 Potassium Channel; Membrane Potentials; Phosphatidylcholines; Phosphatidylethanolamines; Phosphatidylserines; Proteolipids; Recombinant Proteins; Subcellular Fractions; Valinomycin