The use of AFM to study molecular recognition events at an incredible level of sensitivity is currently a very active field of research. In order to get information at the single molecule level, it is mandatory to modify in a precise manner the AFM tip to anchor either ligand or receptor molecules. In the following lines, we review the achievements in tip modifications and illustrate the scope and limitations of the different strategies that have been reported.
Analogues of a synthetic ion channel made from a helical peptide were used to study the mechanism of cation translocation within bilayer membranes. Derivatives bearing two, three, four, and six crown ethers used as ion relays were synthesized, and their transport abilities across lipid bilayers were measured. The results showed that the maximum distance a sodium ion is permitted to travel between two binding sites within a lipid bilayer environment is 11 Å.
A helical 14-residue peptide containing four polar, but uncharged, benzo-21-crown-7 side-chains aligned along one face induces significantly more vesicle leakage than analogous 21-mer or 7-mer peptides.
Ion channel proteins are complex membrane proteins that control and regulate the transport of ions across cell membranes. Because of their involvement in several diseases,' their potential use in biosensors? and their inherent difficulty of isolation, intense efforts have been devoted to the preparation of artificial ion channel^.^ Here, we report a very simple, rapid, and efficient strategy for the preparation of such functional channel molecules. The strategy combines the versatility of solid phase peptide synthesis, the conformational predictability of peptidic molecules, and the solution synthesis of crown ethers with engineerable ion-binding abilities.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.