ABSTRACT
I. INTRODUCTION Since the pioneering work by Morawetz and Hugues [1], it is now recog nized that globular proteins can form tight complexes with polyelectrolytes. These associations may result in soluble species [2] (including complexes with insoluble proteins such as membrane proteins [3]), complex coacervation [4], precipitation [5], or gelation [6]. The preservation of the native structure of the protein seems a general case, as judged by the variety of functional enzyme/polymer complexes that has been studied [3,7-11]. Ob vious practical consequences of this include stabilizing native enzymes, de veloping novel separation methods of proteins for food or pharmaceutical industries [12,13], facilitating dispersions of insoluble proteins for their func tional or structural studies [3], and directing and stabilizing enzymes at the surface of electrodes for biosensors [14]. For each application, a different state of association and dispersion of the proteins should be optimal. Pro vided that the mechanisms of association are well understood, the vast re sources of polymer chemistry together with the possibility of modulating pH, ionic strength, or temperature should make it readily possible to choose the polymer toward specific uses.
