Beta-cyclodextrin modifications as related to enzyme stability in dehydrated systems: supramolecular transitions and molecular interactions

SANTAGAPITA, PATRICIO R.; GOMEZ BRIZUELA, LEISSY; MAZZOBRE, MARIA FLORENCIA; RAMIREZ, HECTOR L.; CORTI, HORACIO ROBERTO; VILLALONGA SANTANA, REYNALDO; BUERA, MARIA DEL PILAR

CARBOHYDRATE POLYMERS

ELSEVIER SCI LTD

Año: 2011 vol. 83 p. 203 - 209

0144-8617

The effect of b-cyclodextrin modifications (polymerization (PCD) and later carboxymethylation (CMPCD)) on their action as enzyme stabilizers was analyzed during freeze-drying and thermal treatment. Combined polymer-trehalose matrices were also employed. Due to their higher Tg values, PCD and CMPCD provided better structural stability to the freeze-dried formulations than b-CD. However, only PCD was a good excipient to protect invertase both in amorphous and supercooled systems. FT-IR revealed increased protein denaturation in the presence of CMPCD, but not in the presence of PCD. Even though all polymers inhibited/delayed trehalose crystallization, only trehalose (T) combined with PCD (PCD+T) and with beta-cyclodextrin (b-CD+T) offered the best stability to the enzyme. In b-CD+T system, trehalose was the main responsible of the protection. In PCD+T system, both additives contributed to improve the enzyme stability. FTIR and DSC were useful to analyze the combined role of molecular and supramolecular interactions on enzyme stability in dehydrated models systems