Single-molecule dynamic force spectroscopy of the fibronectin–heparin interaction

Abstract

The integrity of cohesive tissues strongly depends on the presence of the extracellular matrix, which provides support and anchorage for cells. The fibronectin protein and the heparin-like glycosaminoglycans are key components of this dynamic structural network. In this report, atomic force spectroscopy was used to gain insight into the compliance and the resistance of the fibronectin–heparin interaction. We found that this interaction can be described by an energetic barrier width of 3.1±0.2Å and an off-rate of 0.2±0.1s−1. These dissociation parameters are similar to those of other carbohydrate–protein interactions and to off-rate values reported for more complex interactions between cells and extracellular matrix components. Our results indicate that the function of the fibronectin–heparin interaction is supported by its capacity to sustain significant deformations and considerable external mechanical forces.