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Counterbalance of Stability and Activity Observed for Thermostable Transaminase from Thermobaculum terrenum in the Presence of Organic Solventsстатья
Информация о цитировании статьи получена из
Web of Science
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 15 июля 2021 г.
- Авторы: Bezsudnova Ekaterina Y., Nikolaeva Alena Y., Kleymenov Sergey Y., Petrova Tatiana E., Zavialova Sofia A., Tugaeva Kristina V., Sluchanko Nikolai N., Popov Vladimir O.
- Журнал: Catalysts
- Том: 10
- Номер: 9
- Год издания: 2020
- Первая страница: 1024
- Последняя страница: 1036
- DOI: 10.3390/catal10091024
- Аннотация: Pyridoxal-5’-phosphate-dependent transaminases catalyze stereoselective amination of organic compounds and are highly important for industrial applications. Catalysis by transaminases often requires organic solvents to increase the solubility of reactants. However, natural transaminases are prone to inactivation in the presence of water-miscible organic solvents. Here, we present the solvent tolerant thermostable transaminase from Thermobaculum terrenum (TaTT) that catalyzes transamination between L-leucine and alpha-ketoglutarate with an optimum at 75 °C and increases the activity ~1.8-fold upon addition of 15% dimethyl sulfoxide or 15% methanol at high but suboptimal temperature, 50 °C. The enhancement of the activity correlates with a decrease in the thermal denaturation midpoint temperature. The blue-shift of tryptophan fluorescence suggested that solvent molecules penetrate the hydration shell of the enzyme. Analysis of hydrogen bonds in the TaTT dimer revealed a high number of salt bridges and surface hydrogen bonds formed by backbone atoms. The latter are sensitive to the presence of organic solvents; they rearrange, conferring the relaxation of some constraints inherent to a thermostable enzyme at low temperatures. Our data support the idea that the counterbalance of stability and activity is crucial for the catalysis under given conditions; the obtained results may be useful for fine-tuning biocatalyst efficiency.
- Добавил в систему: Шилова (Завьялова) Софья Александровна