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.

Keywords:

• Alcohol dehydrogenase
• polyglycerol dendrimers
• bound water
• protein stability
• spin-lattice relaxation times

Acknowledgements

This work was partially supported by a Grant-in-Aid for Scientific Research B (JSPS KAKENHI Grant Number 22300165), a Grant-in-Aid for Scientific Research on Innovative Areas “New Polymeric Materials Based on Element-Blocks (No.2401)” (JSPS KAKENHI Grant Number JP15H00748), and an Adaptable and Seamless Technology Transfer Program (A-STEP) through target-driven R & D, Contract No. AS242Z01653P from JSPS. The authors would like to thank Enago (www.enago.jp) for the English language review.