Determination of protein‐protein interactions through aldehyde‐dextran intermolecular cross‐linking

Abstract
A very simple strategy, based on the intermolecular cross‐linking of associated proteins by using aldehyde‐dextrans, has been proposed to detect protein‐protein interactions. Aldehyde‐dextran was able to cross‐link different enzymes composed of several polypeptide chains (e.g., trypsin and penicillin G acylase), proteolyzated proteins (e.g., extracts from porcine pancreas) and finally, an immunocomplex (horseradish peroxidase/anti‐horseradish peroxidase). This cross‐linked immunocomplex could be selectively adsorbed on immobilized anti‐rabbit IgG. The presence of unspecific covalent attachment between unrelated protein molecules was not detected. Thus, this strategy permits the cross‐linking of different protein components and avoids the formation of nonspecific protein‐protein associations.