The gene encoding a family-57-like alpha-amylase in the hyperthermophilic archaeon Methanococcus jannaschii, has been cloned into Escherichia coli. Extremely thermoactive alpha-amylase was confirmed in partially purified enzyme solution of the recombinant culture. This enzyme activity had a temperature optimum of 120 degrees C and a pH optimum 5.0-8.0. The amylase activity is extremely stable against denaturants. Hydrolysis of large sugar polymers with alpha-1-6 and alpha-1-4 linkages yields products including glucose polymers of 1-7 units. Highest activity is exhibited on amylose. The catalyst exhibited a half-life of 50 h at 100 degrees C, among the highest reported thermostabilities of natural amylases.

• MeSH
• alfa-amylasy biosyntéza   genetika   metabolismus   MeSH
• amylosa metabolismus   MeSH
• Escherichia coli metabolismus   MeSH
• glukany metabolismus   MeSH
• klonování DNA MeSH
• koncentrace vodíkových iontů MeSH
• metabolismus sacharidů MeSH
• Methanococcus enzymologie   genetika   MeSH
• molekulární sekvence - údaje MeSH
• rekombinantní proteiny metabolismus   MeSH
• sekvence aminokyselin MeSH
• sekvenční seřazení MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• srovnávací studie MeSH
• Názvy látek
• alfa-amylasy MeSH
• amylosa MeSH
• glukany MeSH
• rekombinantní proteiny MeSH

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.

• MeSH
• Escherichia coli metabolismus   MeSH
• glukany chemie   MeSH
• glykosidhydrolasy chemie   genetika   metabolismus   MeSH
• klonování DNA MeSH
• koncentrace vodíkových iontů MeSH
• Methanococcus enzymologie   genetika   MeSH
• molekulární sekvence - údaje MeSH
• molekulová hmotnost MeSH
• polysacharidy chemie   MeSH
• sekvence aminokyselin MeSH
• sekvenční seřazení MeSH
• stabilita enzymů MeSH
• teplota MeSH
• vápník farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• srovnávací studie MeSH
• Názvy látek
• glukany MeSH
• glykosidhydrolasy MeSH
• polysacharidy MeSH
• vápník MeSH