title: Technical advance: Surface plasmon resonance-based analysis of CXCL12 binding using immobilized lentiviral particles.
abstract: Use of SPR-based biosensors is an established method for measuring molecular interactions. Their application to the study of GPCRs is nonetheless limited to detergent-solubilized receptors that can then be reconstituted into a lipid environment. Using the chemokine receptor CXCR4 and its specific ligand CXCL12, we outline here a highly reproducible biosensor method based on receptor presentation on the surface of lentiviral particles; the approach is simple and does not require the use of antibodies to achieve correct receptor orientation on the sensorchip surface. We measured the kinetic parameters of CXCR4/CXCL12 binding in a single step and in real time and evaluated the effect of GAG presentation of chemokines on this interaction. The data indicate that at low concentrations, soluble heparin modulates CXCR4/CXCL12 interaction and at high concentrations, abrogates binding. These observations suggest that in addition to their known role in modulating local chemokine availability, GAG affect the receptor/ligand interaction, although their influence on affinity parameters is very limited. The method will also be useful for quantifying these biomarkers in biological fluids and for the development of high-throughput screening for their antagonists.
authors: Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Cientificas, Campus de Cantoblanco, Madrid, Spain.
authors: Beatriz
authors: B
authors: Vega
authors: Laura Martínez
authors: LM
authors: Muñoz
authors: Borja L
authors: BL
authors: Holgado
authors: Pilar
authors: P
authors: Lucas
authors: J M
authors: JM
authors: Rodríguez-Frade
authors: Ana
authors: A
authors: Calle
authors: J L
authors: JL
authors: Rodríguez-Fernández
authors: Laura M
authors: LM
authors: Lechuga
authors: José F
authors: JF
authors: Rodríguez
authors: Ricardo
authors: R
authors: Gutiérrez-Gallego
authors: Mario
authors: M
authors: Mellado