Parts | Days | Selection | Search | Downloads | Help
BP: Fachverband Biologische Physik
BP 7: Poster I
BP 7.37: Poster
Monday, March 23, 2009, 17:45–20:00, P3
Single Molecule Force Spectroscopy to Study Receptor / Ligand Interactions — Mathias Salomo1, •Marc Struhalla2, and Friedrich Kremer1 — 1Universität Leipzig, Institut für Experimentelle Physik I, Linnèstraße 5, 04103 Leipig — 2c-LEcta GmbH, Deutscher Platz 5b, 04103 Leipzig
Optical tweezers (OT) are ideally suited to study the interaction of single receptor-ligand bonds. Here we introduce a newly developed assay using optical tweezers to investigate the interactions between Protein A from Staphylococcus aureus, Protein G from Streptococcus spec. and different immunoglobulins. We demonstrate that the rupture forces depend on the loading rate and on the sodium chloride concentration. The measured loading rate effect is well known in the literature and the data we obtained and which were found to be in good agreement with an already published theoretical model can be used to directly determine interaction parameters like the dissociation rate. The dependence of the rupture forces on the salt concentration demonstrates the influence of hydrophobic interactions on the bond strength. Our experimental setup can probe the interaction between a single receptor and its specific ligand under changing conditions and hence offers manifold applications in single molecule biotechnology.