Hydrophobic interactions bind some proteins there, while hydrogen bonding or other forces attach yet other proteins to the hot spot.

Briefly, the ligand is trapped from the bulk solution at the entrance of the ligand-binding pocket and brought into and locked at the binding site by interaction with amino acid residues within the receptor through H-bond and hydrophobic interactions.

Even though results of these studies have at times been contradictory because no standardized methods exist for determining surface hydrophobicity, some kind of hydrophobic interaction apparently occurs between the cell surface and the substratum that would enable the cell to overcome the repulsive forces active within a certain distance from the substratum surface and irreversibly attach.