Berlin 2015 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 41: Protein structure and dynamics I
BP 41.4: Vortrag
Donnerstag, 19. März 2015, 10:30–10:45, H 1058
The initial adsorption stages of fibrinogen at mica and graphite — •Stephan Köhler1,2 and Giovanni Settanni1,3 — 1Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudinger Weg 7, D-55128 Mainz — 2Graduate School Materials Science in Mainz, Staudinger Weg 9, D-55128 Mainz — 3Max Planck Graduate Center mit der Johannes Gutenberg-Universität Mainz, Staudinger Weg 9, D-55128 Mainz
Fibrinogen is a large glycoprotein in the blood of vertebrates. It is an essential factor in blood clotting where it forms fibrin after being activated by thrombin. Furthermore, adsorbed fibrinogen is known to be an important factor for the biocompatibility of materials. The protein contains binding sites for leukocytes and platelets. Consequently, adsorbed fibrinogen has been implicated as a cause for thrombosis and inflammation at implants. The molecular underpinnings of this have been investigated in many experimental studies. These studies often use model surfaces like mica and graphite to investigate the structure of adsorbed fibrinogen.
Here we present the first fully atomistic simulations of the initial adsorption stages of a fibrinogen protomer at such model surfaces. The simulations reveal a weak adsorption at mica that allows frequent desorption and reorientation events. This adsorption is driven by electrostatic interactions between the protein and the silicate surface as well as the counter ion layer. Preferred adsorption orientations for the globular regions are identified. As a contrast to mica, adsorption at graphite is more permanent and the onset of denaturation is observed.