| Autor: |
Eram MS; Department of Biology, University of Waterloo, Waterloo, Ontario, Canada., Ma K; Department of Biology, University of Waterloo, Waterloo, Ontario, Canada. |
| Jazyk: |
angličtina |
| Zdroj: |
Biochemistry and biophysics reports [Biochem Biophys Rep] 2016 Jul 16; Vol. 7, pp. 394-399. Date of Electronic Publication: 2016 Jul 16 (Print Publication: 2016). |
| DOI: |
10.1016/j.bbrep.2016.07.008 |
| Abstrakt: |
Acetohydroxyacid synthase (AHAS) catalyzes the production of acetolactate from pyruvate. The enzyme from the hyperthermophilic bacterium Thermotoga maritima has been purified and characterized ( k cat ~100 s -1 ). It was found that the same enzyme also had the ability to catalyze the production of acetaldehyde and CO 2 from pyruvate, an activity of pyruvate decarboxylase (PDC) at a rate approximately 10% of its AHAS activity. Compared to the catalytic subunit, reconstitution of the individually expressed and purified catalytic and regulatory subunits of the AHAS stimulated both activities of PDC and AHAS. Both activities had similar pH and temperature profiles with an optimal pH of 7.0 and temperature of 85 °C. The enzyme kinetic parameters were determined, however, it showed a non-Michaelis-Menten kinetics for pyruvate only. This is the first report on the PDC activity of an AHAS and the second bifunctional enzyme that might be involved in the production of ethanol from pyruvate in hyperthermophilic microorganisms. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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