Conformational transition in SPR experiments: impact of spacer length, immobilization mode and aptamer density on signal sign and amplitude
Marina Pons, Marine Perenon, Hugues Bonnet, Émilie Gillon, Celio Vallée, Liliane Coche‐Guérente, Éric Defrancq, Nicolas Spinelli, Angéline Van der Heyden, Jérôme Dejeu
Abstract
around 200 nM as demonstrated using a quartz crystal microbalance with dissipation monitoring and isothermal titration calorimetry). We demonstrated that this unconventional signal could be attributed to two opposite contributions: a positive one is afforded by the aptamer recognition and folding whereas a negative one results from the refractive index increment (RII) deviation upon the formation of the complex (ligand/analyte). We also demonstrated that the RII deviation is sensitive to the modification of the sequence flexibility and therefore depends on the anchoring procedure and the spacer length between the anchoring function and the site of recognition.