title: Lack of association between a cationic protein and a cationic fluorosurfactant.
abstract: Surface tension, 19F and 1H NMR spectroscopy, and cryotransmission electron microscopy are used to characterize the state of association in aqueous solutions of a fluorosurfactant CF3(CF2)nSO2NH(CH2)3-4N(CH3)3+ I- (n = 8, 6) with and without lysozyme added. In the absence of lysozyme, we find monomers, small aggregates, and large vesicles to coexist, with the individual fluorosurfactant molecules exchanging slowly (>1 ms) among those states. When both lysozyme and fluorosurfactant are present in the solution, they have no measurable influence on the physical state of the other. In contrast, a hydrogenated cationic surfactant with the same headgroup, hexadecyltrimethylammonium bromide, is shown to associate to lysozyme.
authors.affiliation: Division of Surface Chemistry, Royal Institute of Technology, S-10044 Stockholm, Sweden.
authors.forename: Lubica
authors.initials: L
authors.lastname: Macakova
authors.forename: Lars
authors.initials: L
authors.lastname: Nordstierna
authors.forename: Göran
authors.initials: G
authors.lastname: Karlsson
authors.forename: Eva
authors.initials: E
authors.lastname: Blomberg
authors.forename: István
authors.initials: I
authors.lastname: Furó
mesh_terms: D002412:Cations; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D002627:Chemistry, Physical / Q000379:methods; D020285:Cryoelectron Microscopy; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D009113:Muramidase / Q000737:chemistry*; D017510:Protein Folding; D013499:Surface Properties; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D002412:Cations; D002593:Cetrimonium Compounds; D013501:Surface-Active Agents; D009113:Muramidase; D000077286:Cetrimonium