1. Cryoprotective ability of betaine-type metabolite analogs during freezing denaturation of enzymes.
- Author
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Nakagawa, Yuichi, Sota, Masahiro, and Koumoto, Kazuya
- Subjects
CRYOPROTECTIVE agents ,BETAINE ,METABOLITES ,ENZYMES ,FREEZING ,FISH research - Abstract
Objective: To evaluate an analog library of betaine-type cellular metabolites, which are naturally found in polar fish for survival in subzero temperatures, for preventing denaturation of enzymes during freezing. Results: Comparison of the cryoprotective ability of reported cryoprotectants, such as dimethylsulfoxide, glycerol, ectoine, hydroxyectoine, and trehalose, with betaine-type analogs using α-glucosidase revealed that analogs introducing C-C alkyl chains into an ammonium cation retained 20 % higher activity than the control cryoprotectants at the same concentration. In particular, the analog possessing triplicate n-butyl chains showed a profound effect. It allowed retention of enzyme activity to 95 % even after 100 freeze-thaw cycles, while addition of the control cryoprotectants decreased the activity to 10-20 %. The cryoprotective ability of betaine-type analogs can be applied not only to α-glucosidase but also other enzymes such as β-glucosidase, alkaline phosphatase, lactose dehydrogenase, sulfatase, and horseradish peroxidase. Conclusion: Synthetic betaine-type metabolite analogs possess practicable cryoprotective ability for various enzymes, and are considerably superior to previously reported cryoprotectants. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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