CHARACTERIZATION OF CHITOSAN - ACID PROTEINS SOLUBLE AND NON-SOLUBLE COMPLEXES FORMATION

PICÓ, G.A.; GALANTE, M.; BOERIS, V.; BELLUZO, M. S.

Lausanne

Simposio; 9th International Symposium on Polyelectrolytes - ISP 2012; 2012

Chitosan (Chi), a natural polycation, is commonly used for the separation and purification of enzymes by precipitation. Its interaction with acid proteins (bovine abomasums pepsin, PEP, bovine liver catalase, CAT and bovine serum albumin, BSA) was studied to understand the molecular mechanism of complexes formation and precipitation. The hidrodynamic size of the soluble complexes was determined by dynamic light scattering in the pH range 3.0 to 4.5. It was found that the diameter of the complexes decreases (Chi-PEP: from 410 to 175 nm) when increasing pH. This fact may be due to the increase in the net negative electric charge of the acid proteins, allowing a better neutralization of the positive electric charges of Chi