[en] The interaction of AOT reverse micelles with Met-enkephalin, the pancreatic secretory trypsin inhibitor (PSTI) and the epidermal growth factor (EGF) is examined by NMR methods and the three systems are compared. While Met-enkephalin adopts a folded conformation, PSTI appears to become highly flexible, suggestive of a non-specific interaction with the micelles. On the other hand, the EGF spectrum shows that, although the main globular features of the protein are retained in the presence of AOT, the C-terminal fragments has to rearrange its conformation when put in contact with the micelle wall. (Auth.)