title: Surfactin at the Water/Air Interface and in Solution.
abstract: The lipopeptide surfactin produced by certain strains of Bacillus subtillis is a potent biosurfactant with high amphiphilicity and a strong tendency for self-aggregation. Surfactin possesses a number of valuable biological properties such as antiviral, antibacterial, antifungal, and hemolytic activities. Owing to these properties, in addition to the general advantages of biosurfactants over synthetic surfactants, surfactin has potential biotechnological and biomedical applications. Here, the aggregation properties of surfactin in solution together with its behavior at the water/air interface were studied using classical molecular dynamics simulations (MD) at three different pH values. Validation of the MD structural data was performed by comparing neutron reflectivity and volume fraction profiles computed from the simulations with their experimental counterparts. Analysis of the MD trajectories supported conclusions about the distribution, conformations, and interactions of surfactin in solution and at the water-air interface. Considering altogether, the work presented provides atomistic models for the rationalization of some of the structural and dynamic characteristics as well as the modes of action of surfactin at different pH values.
authors.affiliation: Department of Chemistry, King's College London , Britannia House, 7 Trinity Street, London SE1 1DB, U.K.
authors.forename: Javier
authors.initials: J
authors.lastname: Iglesias-Fernández
authors.affiliation: Department of Chemistry, King's College London , Britannia House, 7 Trinity Street, London SE1 1DB, U.K.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Darré
authors.affiliation: Institute for Computational Molecular Science (035-07), College of Science and Technology, Temple University , 1901 N. 13th Street, Philadelphia, Pennsylvania 19122, United States.
authors.forename: Axel
authors.initials: A
authors.lastname: Kohlmeyer
authors.affiliation: Physical & Theoretical Chemistry Laboratory, University of Oxford , South Parks Road, Oxford OX1 3QZ, U.K.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Thomas
authors.affiliation: Department of Microbiology, Faculty of Medicine, Nursing & Health Sciences, Clayton, Monash University , Melbourne, Victoria 3800, Australia.
authors.forename: Hsin-Hui
authors.initials: HH
authors.lastname: Shen
authors.affiliation: Department of Chemistry, King's College London , Britannia House, 7 Trinity Street, London SE1 1DB, U.K.|Chemistry Research Laboratory, University of Oxford , Mansfield Road, Oxford OX1 3TA, U.K.
authors.forename: Carmen
authors.initials: C
authors.lastname: Domene
mesh_terms: D055666:Lipopeptides / Q000737:chemistry*; D010456:Peptides, Cyclic / Q000737:chemistry*; D012996:Solutions; D014867:Water / Q000737:chemistry*
chemical_list: D055666:Lipopeptides; D010456:Peptides, Cyclic; D012996:Solutions; D014867:Water; C009365:surfactin peptide