Novel, thermostable family-13-like glycoside hydrolase from Methanococcus jannaschii.
A novel glycoside hydrolase from the hyperthermophilic archaeon Methanococcus jannaschii has been cloned into Escherichia coli. Extremely thermoactive and thermostable amylolytic activity was confirmed in partially purified enzyme solution. This enzyme exhibited a temperature optimum of 100 degrees C and a pH optimum pH 5.0-8.0. Hydrolysis of large 1,6-alpha- and 1,4-alpha-linked polysaccharides yielded glucose polymers of 1-7 units. Incubation with amylose displayed the highest activity. The catalyst was activated and stabilized by Ca2+ and exhibited extreme thermostability at 100 degrees C with a half-life of 78 h.
Kim
J W
JW
Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, Iowa 52242, USA.
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D000595:Amino Acid Sequence; D002118:Calcium / Q000494:pharmacology; D003001:Cloning, Molecular; D004795:Enzyme Stability; D004926:Escherichia coli / Q000378:metabolism; D005936:Glucans / Q000737:chemistry; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D017017:Methanococcus / Q000201:enzymology* / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry; D016415:Sequence Alignment; D013696:Temperature
D005936:Glucans; D011134:Polysaccharides; D006026:Glycoside Hydrolases; D002118:Calcium