Applications of Calorimetric Techniques in the formation of Protein-Polyelectrolytes Complexes

ROMANINI, DIANA; BRAIA, MAURICIO; PORFIRI, MA. CECILIA

Applications of Calorimetry in a Wide Context - Differential Scanning Calorimetry, Isothermal Titration Calorimetry and Microcalorimetry

IntTech, Open Sciences, Open minds

Año: 2013; p. 105 - 128

Precipitation of polyelectrolyte-protein complex plays an important role in different processes in biotechnology. Methods based in the formation of insoluble complexes provide an effective technique for purification and concentration of a protein in a dilute solution and also allow immobilizing and stabilizing enzymes in order to produce in bioreactors. Although protein precipitation with these charged polymers (polyelectrolytes) has been studied for many years, few theoretical studies have been directed toward understanding the mechanism of precipitation. Because of charged polymer and protein have a hydrophobic and nonpolar regions, the complex formation may be driven by coulombic forces or hydrophobic interactions. Differential scanning calorimetry (DSC) and Isothermal titration calorimetry (ITC) are required to complement the turbidimetric and enzymatic activity studies of polyelectrolyte-protein complex formation. Combining of these techniques provide a useful tool to understand the nature of interactions, affinity and stability of an enzyme. Polymer-protein complex; enzyme; polyelectrolyte; differential scanning calorimetry; isothermal titration calorimetry