Regensburg 2010 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 5: Posters: Biopolymers and Biomaterials
BP 5.10: Poster
Montag, 22. März 2010, 17:15–20:00, Poster B1
Optical tweezers to investigate receptor/ligand interactions on a single contact level — •Carolin Wagner1, David Singer2, Mathias Salomo3, Ralf Hoffmann2, and Friedrich Kremer1 — 1University of Leipzig, Department for molecule Physics, Leipzig, Germany — 2University of Leipzig, Institut Institut für bioanalytische Chemie, Leipzig, Germany — 3Fraunhofer-Institut für Zelltherapie und Immunologie, Leipzig, Germany
The extraordinary features of optical tweezers having a nm- resolution in positioning a micron-sized colloid and an accuracy of (+/-50 fN) in measuring the forces acting on it, enable one to study the interaction within a single receptor/ligand-contact. By use of dynamic force spectroscopy (DFS), the specific binding of the monoclonal antibody HPT-110 to a synthetic doubly phosphorylated tau-peptide is investigated on a single contact level. Amongst others, the massive accumulation of tangles that mainly consist of hyperphosphorylated tau-proteins is characteristic for Alzheimer's disease. Single-molecule DFS enables the investigation of the energy landscape of the bond and benefits from the fact that only minimal amounts of the sample are necessary. It is demonstrated that the rupture force depends on the loading rate. This effect is well known in the literature and the data obtained were found to be in good agreement with an already published theoretical model. By use of this model, the off-rate at zero force of 0,54 s-1 is determined.