Dresden 2011 – scientific programme
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BP: Fachverband Biologische Physik
BP 18: Single-Molecule Biophysics II
BP 18.4: Talk
Tuesday, March 15, 2011, 15:00–15:15, ZEU 250
Getting closer to the nature of specific bonds: Dynamic force spectroscopy on the binding of monoclonal antibodies and tau peptides — •Wagner Carolin1, Singer David2, Hoffmann Ralf2, and Kremer Friedrich1 — 1Leipzig University, Department of Molecular Physics, Leipzig, Germany — 2Leipzig University, Center for Biotechnology and Biomedicine, Leipzig, Germany
Optical tweezers-assisted dynamic force spectroscopy (DFS) is employed to investigate specific receptor/ligand-bonds on a single contact level. Here, the specific binding of two monoclonal antibodies (mAbs), HPT-110 and HPT-104, to synthetic tau-peptides with different phosphorylation pattern is analyzed. The specificity of HPT-110 to the tau-peptide containing a phosphorylation at Ser235 and of HPT-104 to the tau-peptide containing a phosphorylation at Thr231 is confirmed. Additionally, our approach allows for a detailed characterization of the unspecific interactions that are observed between HPT-104 and the peptide phosphorylated only at Ser235 and between HPT-110 and the peptide phosphorylated only at Thr231. By analyzing the measured rupture-force distributions it is possible to separate unspecific from specific interactions. Thereby for the latter characteristic parameters like the lifetime of the bond without force t0, the characteristic length xts and the free energy of activation DG are determined. The results are in accordance with conventional ELISA tests but offer a much more refined insight.