Valinomycin is a potent antibiotic which functions as an ion

Valinomycin is a potent antibiotic which functions as an ionophore, I, e, disrupts ionic balance of cells by selectively transporting K^+ ions across biological membranes. Based on the structure provided below, provide an explanation of how Valinomycin interacts with membranes on a molecular level. Also, indicate with a schematic diagram which functional groups are most likely to interact with K^+ ions. What feature of the molecule makes it more selective towards K^+ ions over Na^+ ions?

Solution

the shape and size this molecular duality is principle explanation behind its binding properties. K ions must give up their water of hydration to pass through the pore. K+ particles are octahedrally organized in a square bipyramidal geometry by 6 carbonyl bonds from Val. In this space of 1.33 Angstrom, Na+ with its 0.95 Angstrom span, is altogether littler than the channel, it implying that Na+ can\'t shape ionic bonds with the amino acids of the pore at identical vitality as those it surrenders with the water atoms. This prompts to a 10,000x selectivity for K+ particles over Na+. For polar solvents, valinomycin will for the most part open the carbonyls to the dissolvable and in nonpolar solvents the isopropyl gatherings are found transcendently on the outside of the molecule.