title: Quantitative analysis of molecular partition towards lipid membranes using surface plasmon resonance.
abstract: Understanding the interplay between molecules and lipid membranes is fundamental when studying cellular and biotechnological phenomena. Partition between aqueous media and lipid membranes is key to the mechanism of action of many biomolecules and drugs. Quantifying membrane partition, through adequate and robust parameters, is thus essential. Surface Plasmon Resonance (SPR) is a powerful technique for studying 1:1 stoichiometric interactions but has limited application to lipid membrane partition data. We have developed and applied a novel mathematical model for SPR data treatment that enables determination of kinetic and equilibrium partition constants. The method uses two complementary fitting models for association and dissociation sensorgram data. The SPR partition data obtained for the antibody fragment F63, the HIV fusion inhibitor enfuvirtide, and the endogenous drug kyotorphin towards POPC membranes were compared against data from independent techniques. The comprehensive kinetic and partition models were applied to the membrane interaction data of HRC4, a measles virus entry inhibitor peptide, revealing its increased affinity for, and retention in, cholesterol-rich membranes. Overall, our work extends the application of SPR beyond the realm of 1:1 stoichiometric ligand-receptor binding into a new and immense field of applications: the interaction of solutes such as biomolecules and drugs with lipids.
authors.affiliation: Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Portugal.
authors.forename: Tiago N
authors.initials: TN
authors.lastname: Figueira
authors.affiliation: Institut Pasteur, Unité de Virologie Structurale, Département de Virologie, F-75724 Paris Cedex 15, France.
authors.forename: João M
authors.initials: JM
authors.lastname: Freire
authors.affiliation: Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Portugal.
authors.forename: Catarina
authors.initials: C
authors.lastname: Cunha-Santos
authors.affiliation: Laboratori d'Innovació en Processos i Productes de Síntesi Orgànica (LIPPSO), Departament de Química, Universitat de Girona, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Heras
authors.affiliation: Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Gonçalves
authors.affiliation: Department of Pediatrics, Columbia University Medical Center, New York, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Moscona
authors.affiliation: Department of Pediatrics, Columbia University Medical Center, New York, USA.
authors.forename: Matteo
authors.initials: M
authors.lastname: Porotto
authors.affiliation: Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Salomé Veiga
authors.affiliation: Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Portugal.
authors.forename: Miguel A R B
authors.initials: MA
authors.lastname: Castanho
mesh_terms: D004723:Endorphins / Q000737:chemistry; D000077560:Enfuvirtide; D015700:HIV Envelope Protein gp41 / Q000737:chemistry; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry*; D008563:Membrane Lipids / Q000737:chemistry*; D008954:Models, Biological; D010446:Peptide Fragments / Q000737:chemistry; D020349:Surface Plasmon Resonance; D013499:Surface Properties
chemical_list: D004723:Endorphins; D015700:HIV Envelope Protein gp41; D008051:Lipid Bilayers; D008563:Membrane Lipids; D010446:Peptide Fragments; C019448:kyotorphin; D000077560:Enfuvirtide