Temperature-induced recovery of a bioactive enzyme using polyglycerol dendrimers: correlation between bound water and protein interaction.

ABSTRACT

Enzyme application has gained importance over the past decade in bioprocess, biomedical, and pharmaceutical fields. We found that polyglycerol dendrimers (PGDs), which are biocompatible molecules, can recover alcohol dehydrogenase (ADH) from aqueous solution under elevated temperature. A low concentration of PGD (5 wt.%) is sufficient for the recovery of high enzymatic activity, although a high concentration (25-75 wt.%) of glycerol is generally required to stabilize ADH. The enzymatic activity of ADH in suspension with PGDs is over 60% but it is only 10% in that with glycerol. The results of osmolarity and spin-lattice relaxation time (T1) of water measurements in the presence of PGDs suggest that increased amounts of bound water to PGD molecules trigger aggregation along with the direct interaction with ADH. PGDs therefore represent good potential additives for direct recovery of enzymes from aqueous solutions.