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.

Plant defensin PvD1 modulates the membrane composition of breast tumour-derived exosomes

“…Consequently, K p was determined only for synthetic SUVs (Table 1). 47 Our SPR approach also demonstrates that PvD 1 is able to bind to MCF-7 exosomes and to the synthetic membranes composed of the major lipids represented in the exosomal membrane ( Fig. 7A and S5 †).…”

“…The associated steady-state response values for PvD 1 were collected from individual sensorgrams at t = 250 s. The data were analysed using the partition relationship previously developed by our group. 47…”

“…54,55 We also prepared vesicles containing glucosylceramide (GlucCer), proposed to be important for PvD 1 's cytotoxic activity. 31 Applying the steadystate model developed by our group, 47 we retrieved partition coefficients, (K p ), for quantifying the relative solute ( peptide) distribution in the lipid and aqueous phases, and the lipid : solute molar ratio at the membrane saturation (σ) for each SUVs' type. 47 The obtained K p and σ values are presented in Table 1 and the fits of the partition formalism to experimental data are depicted in Fig.…”

“…Data were fitted to the steady state model described elsewhere. 47 Each data point represents an average from experiments performed on different days using independently prepared SUVs.…”

ZnO for performance enhancement of surface plasmon resonance biosensor: a review

“…The development of SPR is important in many fields such as agricultural and food safety [1], medical diagnosis [2], environmental safety control [3] and industrial monitoring [4]. The major application of SPR biosensor is for detection of a variety of biomolecules such as lipid [5], peptides [6], receptor [7], nucleic acid [8], protein [9] and antibodies [10]. The SPR technique has not only been used for biosensing purposes but also in characterizing a broad range of material thin films [11].…”