Structure/function relationships of several biopolymers as related to invertase stability in dehydrated systems

SANTAGAPITA, PATRICIO R.; GÓMEZ BRIZUELA, L.; MAZZOBRE, MARÍA F.; RAMIREZ, H.; CORTI, H.R.; VILLALONGA SANTANA, R.; BUERA, MARÍA DEL P.

BIOMACROMOLECULES

American Chemical Society

Lugar: Washington; Año: 2008 vol. 9 p. 741 - 747

1525-7797

Structure/function relationships of different biopolymers (alginate, dextran or b-cyclodextrin) were analyzed as single excipients or combined with trehalose in relation to their efficiency as enzyme stabilizers in freeze-dried formulations, and compared to trehalose. Particularly, a novel synthesized polymer b-cyclodextrin-branched alginate (b-CD-A) was employed as excipient. During freeze-drying, the polymers or their mixtures did not confer better protection to invertase compared to trehalose. b-CD-A (with or without trehalose), b-cyclodextrin (b-CD) or dextran with trehalose were the best protective agents during thermal treatment, while b-CD and alginate showed a negative effect on invertase activity preservation. The b-CD linked alginate combined the physical stability provided by alginate with the stabilization of hydrophobic regions of the enzyme provided by cyclodextrin. b-CD-A was effective even at conditions at which trehalose lost its protective effect. A relatively simple covalent combination of two biopolymers significantly affected their functionalities and, consequently, their interactions with proteins, modifying enzyme stability patterns.