title: Dendrimer functionalization of gold surface improves the measurement of protein-DNA interactions by surface plasmon resonance imaging.
abstract: Surface Plasmon Resonance imaging (SPRi) is a label free technique typically used to follow biomolecular interactions in real time. SPRi offers the possibility to simultaneously investigate numerous interactions and is dedicated to high throughput analysis. However, precise determination of binding constants between partners is not highly reliable. We report here a dendrimer functionalization of gold surface that significantly improves selectivity of the detection of protein-DNA interactions. We showed that amino-gold surface functionalization with phosphorus dendrimers of fourth generation (G4) allowed complete coverage of the gold surface and the increase of the surface roughness. We optimized the conditions for DNA probe deposition to allow accurate detection of a well-known protein-DNA interaction involved in bacterial chromosome segregation. Using this G4-functionalized surface, the specificity of the SPRi response was significantly improved allowing discrimination between protein and DNA interactions of different strengths. Kinetic constants similar to those obtained with other techniques currently used in molecular biology were only obtained with the G4 dendrimer functionalized surface. This study demonstrated the benefit of using dendrimeric surfaces for sensitive high throughput SPRi analysis.
authors.affiliation: Université de Toulouse; INSA, UPS, INP; LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France.
authors.forename: Flavien
authors.initials: F
authors.lastname: Pillet
authors.forename: Aurore
authors.initials: A
authors.lastname: Sanchez
authors.forename: Cécile
authors.initials: C
authors.lastname: Formosa
authors.forename: Marjorie
authors.initials: M
authors.lastname: Séverac
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Trévisiol
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Bouet
authors.forename: Véronique
authors.initials: V
authors.lastname: Anton Leberre
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004247:DNA / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D050091:Dendrimers / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*; D013499:Surface Properties
chemical_list: D004268:DNA-Binding Proteins; D050091:Dendrimers; D006046:Gold; D004247:DNA