Interaction and complex formation between catalase and cationic

BOERIS, V; ROMANINI, D.; B, FARRUGGUA; G. PICO

INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

ELSEVIER SCIENCE BV

Lugar: Asnterdam; Año: 2009 vol. 45 p. 103 - 108

0141-8130

Interactions between catalase and the cationic polyelectrolytes: chitosan and Eudragit E100 have been investigated owing to their scientific and technological importance. These interactions have been characterized by turbidimetry, circular dichroism and fluorescence spectroscopy. It was found that the catalase conformation does not change significantly during the chain entanglements between the protein and the polyelectrolytes. The effects of pH, ionic strength and anions which modify the water structure were evaluated on the polymer–protein complex formation. A net coulombic interaction force between them was found since the insoluble complex formation decreased after the NaCl addition. Both polymers were found to precipitate around 80% of the protein in solution. No modification of the tertiary and secondary protein structure or the enzymatic activitywas observed when the precipitatewas dissolved by changing the pH of the medium. Chitosan and Eudragit E100 proved to be a useful framework to isolate catalase or proteins with a slightly acid isoelectrical pH by means of precipitation. ©