Abstract
An exo-beta-D-glucosaminidase gene (PH0511) was cloned from the hyperthermophilic archaeon, Pyrococcus horikoshii, and expressed in Escherichia coli. The purified protein showed a strong exo-beta-D: -glucosaminidase activity by TLC analysis. DTT (50 mM) had little effect on its homodimeric structure during SDS-PAGE. The enzyme was optimally active at 90 degrees C (over 20 min) and pH 6. It had a half-life of 9 h at 90 degrees C and is the most thermostable glucosaminidase described up to now. The activity was not inhibited by ethanol, 2-propanol, DMSO, PEG-400, denaturing agents SDS (5%, w/v), urea, guanidine hydrochloride (5 M) and Mg(2+), Mn(2+), Co(2+), Ca(2+), Sr(2+), Ni(2+) (at up to 10 mM).
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Cations, Divalent
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Cloning, Molecular
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Dimerization
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Dimethyl Sulfoxide / chemistry
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Dithiothreitol / chemistry
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Enzyme Stability
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Escherichia coli / metabolism
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Guanidine / chemistry
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Hexosaminidases / biosynthesis*
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Hexosaminidases / chemistry
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Hexosaminidases / isolation & purification
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Hydrogen-Ion Concentration
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Pyrococcus horikoshii / enzymology*
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Recombinant Proteins / antagonists & inhibitors
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Recombinant Proteins / biosynthesis
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Recombinant Proteins / isolation & purification
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Sodium Dodecyl Sulfate / chemistry
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Temperature
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Urea / chemistry
Substances
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Cations, Divalent
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Recombinant Proteins
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Sodium Dodecyl Sulfate
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Urea
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Hexosaminidases
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exo-beta-D-glucosaminidase
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Guanidine
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Dithiothreitol
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Dimethyl Sulfoxide