AVS 47th International Symposium
    Biomaterial Interfaces Wednesday Sessions
       Session BI-WeP

Paper BI-WeP9
Conformational Changes of the Extracellular-matrix Protein Fibronectin Induced by Force Spectroscopy

Wednesday, October 4, 2000, 11:00 am, Room Exhibit Hall C & D

Session: Poster Session
Presenter: Y. Oberdoerfer, WWU Muenster, Germany
Authors: Y. Oberdoerfer, WWU Muenster, Germany
H. Fuchs, WWU Muenster, Germany
A. Janshoff, WWU Muenster, Germany
Correspondent: Click to Email
Since its invention, force spectroscopy by SFM became a powerful instrument to study the structure, mechanism and behaviour of polymers. Especially for biopolymers it is important to be able to perform these studies in a native environment, an advantage which is provided by SFM. In this work we studied conformational changes of the extracellular-matrix protein fibronectin and provide direct proof for the presence of the protein on the cantilever verifying whether it was pulled on the polymer or not. Fibronectin is a modular protein consisting of three different FN-domains: FN I, FN II and FN III. These three domains differ in the number of their appearance in one single fibronectin polymer and also in the number of amino-acids. Extending fibronectin during a force-measurement results in unfolding events of single domains can be distinguish in a force-curve due to the elongation of the polymer itself and also the absolute number of unfolded domains. In this way it is possible to determine whether a FN I-, FN II- or FN III-domain was unfolded. Another topic that should be presented is the possibility to make an elemental mapping of a cantilever surface by means of SIMS and SNMS to determine if the investigated polymer was attached to the probe. With this kind of measurement one can verify if unfolding events occurring in a force-curve arise from the substance itself or any kind of contamination.