Hyperthermostable acetyl xylan esterase.
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.
Affiliation: Institut f. Mikrobiologie und Genetik, Georg-August-Universität, Grisebachstr. 8, D-37077 Goettingen, Germany.Show MeSH
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Mentions: The molecular mass of AxeA as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) (Fig. 1) was in full accordance with the theoretical molecular mass calculated from the axeA‐derived sequence (37 kDa). Analytical gel filtration with a Superdex 200 prep grade column equilibrated with 50 mM TRIS‐HCl pH 8.0, 150 mM NaCl, yielded two symmetrical peaks corresponding to molecular masses of 229 and 74.4 kDa (Fig. 2). The protein from each of the peak fractions displayed similar specific esterase activity and yielded a single 37 kDa band after SDS‐PAGE analysis. These data indicate that active recombinant AxeA is found as a homohexamer and a homodimer respectively.
Affiliation: Institut f. Mikrobiologie und Genetik, Georg-August-Universität, Grisebachstr. 8, D-37077 Goettingen, Germany.