Laboratoire de Synthèse et Physicochimie des Molécules d'Intèrêt Biologiques, Groupe de Biochimie des Protèines, UMR CNRS 5068, Bât 4R3, Université Paul Sabatier, F-31062 Toulouse, France.
Abstract
How can enzymes be protected against denaturation and proteolysis while keeping them in a fully functional state? One solution is to encapsulate the enzymes into liposomes, which enhances their stability against denaturation and proteases. However, the permeability barrier of the lipid membrane drastically reduces the activity of enzyme entrapped in the liposome by reducing the internal concentration of the substrate. To overcome this problem, we permeabilized the wall of the liposome by reconstitution of a porin from Escherichia coli. In this way, we recovered the full functionality of the enzyme while retaining the protection against denaturation and proteolytic enzymes. Copyright 2001 John Wiley & Sons, Inc.