Using 3-D dense packing models to predict surface tension change due to protein adsorption
Joshua W. Lampe, Portonovo S. Ayyaswamy and David M. Eckmann
Recent experimental evidence suggests that adsorption of human blood-borne proteins of varying size and composition is more similar than different. Dense sphere packing models have explained the observed regularity of human blood borne protein adsorption as a result of the dominant role of the solvent in the adsorption process. After evaluating this model, we find that a dependence on molecular volume, instead of molecular weight, is more appropriate. In addition, we explore the role of adsorption-induced conformation or orientation changes, and demonstrate that this model can accommodate volume invariant shape changes but not volume variant shape changes. The molecular volume can be applied to non-spherical molecules such as fibrinogen and captures differences between BSA, multi-layer, and HSA, monolayer, adsorption. These findings confirm the importance of the solvent in protein adsorption, elucidate the importance of molecular volume on surface tension change, and suggest that this model is generally applicable.
Keywords: Adsorption, protein adsorption, reversible adsorption, gas embolism