Adsorption of plasma proteins on hydrophobic surfaces. II. Fibrinogen and fibrinogen-containing protein mixtures.

The adsorption of fibrinogen from single solution and from mixed solution with albumin and gamma-globulin has been followed at the air-buffer, isooctane-buffer, and methylene iodide-buffer interfaces by the pendant drop technique. Fibrinogen is shown to form substantial coherent films on isooctane and methylene iodide, suggesting considerable unfolding and lateral association. From this, a novel hypothesis has been proposed to account for the dominance of fibrinogen adsorption from mixed solutions on certain hydrophobic surfaces, in which the spreading pressure of rapidly unfolding fibrinogen molecules is sufficient to desorb other plasma proteins.