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Hyperthermostable acetyl xylan esterase.

Drzewiecki K, Angelov A, Ballschmiter M, Tiefenbach KJ, Sterner R, Liebl W - Microb Biotechnol (2009)

Bottom Line: Thermotoga maritima AxeA represents the most thermostable acetyl xylan esterase known to date.Differential scanning calorimetry analysis of the thermal stability of AxeA corroborated its extreme heat resistance.A multi-phasic unfolding behaviour was found, with two apparent exothermic peaks at approximately 100-104 °C and 107.5 °C.

View Article: PubMed Central - PubMed

Affiliation: Institut f. Mikrobiologie und Genetik, Georg-August-Universität, Grisebachstr. 8, D-37077 Goettingen, Germany.

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Temperature inactivation kinetics of recombinant AxeA at 70°C, 90°C and 98°C. The purified enzyme (at a concentration of 0.3 µg µl−1) was incubated in the absence of substrate at the respective temperatures, samples were withdrawn and the residual activity was determined with pNP‐acetate as described in Experimental procedures.
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f4: Temperature inactivation kinetics of recombinant AxeA at 70°C, 90°C and 98°C. The purified enzyme (at a concentration of 0.3 µg µl−1) was incubated in the absence of substrate at the respective temperatures, samples were withdrawn and the residual activity was determined with pNP‐acetate as described in Experimental procedures.

Mentions: Using a 10 min assay in 100 mM sodium phosphate buffer at pH 5.5 and chemically acetylated xylan as the substrate (for each temperature a control reaction without enzyme was necessary to account for non‐enzymatic deacetylation; see Experimental procedures for details), the maximum activity of AxeA was measured at 90°C (Fig. 3). The influence of increasing temperature on AxeA inactivation, which was determined by incubation of pure AxeA at a concentration of 330 µg ml−1 in 50 mM sodium phosphate buffer pH 6.5 in the absence of substrate at various temperatures, withdrawing aliquots and measuring the residual activity with the pNP‐acetate standard assay, is depicted in Fig. 4.


Hyperthermostable acetyl xylan esterase.

Drzewiecki K, Angelov A, Ballschmiter M, Tiefenbach KJ, Sterner R, Liebl W - Microb Biotechnol (2009)

Temperature inactivation kinetics of recombinant AxeA at 70°C, 90°C and 98°C. The purified enzyme (at a concentration of 0.3 µg µl−1) was incubated in the absence of substrate at the respective temperatures, samples were withdrawn and the residual activity was determined with pNP‐acetate as described in Experimental procedures.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3815950&req=5

f4: Temperature inactivation kinetics of recombinant AxeA at 70°C, 90°C and 98°C. The purified enzyme (at a concentration of 0.3 µg µl−1) was incubated in the absence of substrate at the respective temperatures, samples were withdrawn and the residual activity was determined with pNP‐acetate as described in Experimental procedures.
Mentions: Using a 10 min assay in 100 mM sodium phosphate buffer at pH 5.5 and chemically acetylated xylan as the substrate (for each temperature a control reaction without enzyme was necessary to account for non‐enzymatic deacetylation; see Experimental procedures for details), the maximum activity of AxeA was measured at 90°C (Fig. 3). The influence of increasing temperature on AxeA inactivation, which was determined by incubation of pure AxeA at a concentration of 330 µg ml−1 in 50 mM sodium phosphate buffer pH 6.5 in the absence of substrate at various temperatures, withdrawing aliquots and measuring the residual activity with the pNP‐acetate standard assay, is depicted in Fig. 4.

Bottom Line: Thermotoga maritima AxeA represents the most thermostable acetyl xylan esterase known to date.Differential scanning calorimetry analysis of the thermal stability of AxeA corroborated its extreme heat resistance.A multi-phasic unfolding behaviour was found, with two apparent exothermic peaks at approximately 100-104 °C and 107.5 °C.

View Article: PubMed Central - PubMed

Affiliation: Institut f. Mikrobiologie und Genetik, Georg-August-Universität, Grisebachstr. 8, D-37077 Goettingen, Germany.

Show MeSH
Related in: MedlinePlus