Dresden 2014 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 52: Biomaterials and Biopolymers (joint session with BP) II
CPP 52.6: Talk
Thursday, April 3, 2014, 16:15–16:30, ZEU 222
Determining the Specificity of Monoclonal Antibody HPT-101 to Tau-Peptides with Optical Tweezers — •Tim Stangner1, Carolin Wagner1, David Singer2, Stefano Angioletti-Uberti3, Christof Gutsche1, Joachim Dzubiella3, Ralf Hoffmann2, and Friedrich Kremer1 — 1University of Leipzig, Department of Experimental Physics I, D-04103 Leipzig, Germany — 2University of Leipzig, BBZ, D-04103 Leipzig, Germany — 3Humboldt University Berlin, Department of Physics, Berlin 12489, Germany
Optical tweezers-assisted dynamic force spectroscopy (DFS) is employed to investigate specific receptor/ligand bindings on the level of single binding events. Here, the binding of the phosphorylation-specific antibody HPT-101 to tau-peptides (pThr231/pSer235) with two potential phosphorylation sites is analyzed. According to ELISA-measurements, the antibody binds only specificity to the double-phosphorylated tau-peptide. It is shown by DFS that HPT-101 binds also to each sort of the mono-phosphorylated peptides. By analyzing the measured rupture-force distributions characteristic parameters are determined for all interactions. Using the extracted bond parameters, we build a simple theoretical model to predict features of the unbinding process for the double-phosphorylated peptide purely based on data on the monophosphorylated ones. Furthermore we introduce a method to estimate the relative affinity of the bonds. The values obtained for this quantity are in accordance with ELISA, showing how DFS can offer important insights about the dynamic binding process that are not accessible with this common and widespread assay.