Aspecific and specific intermolecular interactions in aqueous media.

Aspecific as well as specific interactions involve the same noncovalent forces, consisting of Lifshitz-van der Waals, Lewis acid/base, electrostatic, and thermal or Brownian movement interactions. In vivo, aspecific interactions between, e.g., cells and/or biopolymers usually are repulsive, while specific interactions are always attractive. The differences between the two classes of interactions can be shown to lie in the fact that aspecifically interacting bodies are large, while specifically interacting sites are small, or have a small radius of curvature, and in the fact that aspecifically interacting surfaces are homogeneous, whereas specific sites have a heterogeneous composition.