Abstract
As an eminent ambassador of STEM and renowned NMR spectroscopist, Frances Separovic is an internationally famous name, but could it also be a valuable membrane-active peptide sequence? Her name has been used as an amino acid sequence (FS), successfully synthesised, oxidised, and put into contact with membrane models to investigate any serendipitous activity. The 3D structure of the cyclic FS was determined in dodecylphosphocholine (DPC) micelles by solution NMR spectroscopy. FS displayed a twisted bend separating a helical stretch and an unstructured segment. Using solid-state NMR spectroscopy, the effect of FS on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl-sn-glycero-3-phosphoserine (DMPS) lipid bilayers was studied. FS did not strongly disturb the neutral membrane surface but likely inserted into their hydrophobic core without a strong effect on the lipid dynamics, while perturbation of the negatively charged membranes remained at the headgroup interface with a strong effect on the lipid dynamics. This study demonstrated that FS is a candidate for discovering potential future therapeutic activities.