Abstract: The gene APE1547 from an archeaon Aeropyrum pernix K1 were cloned and expressed in E. coli BL21. The recombinant enzyme shows an esterase activity and its optimum reaction temperature was 90 ℃. In this paper, the stability of a hyperthermophilic esterase APE1547 from an archeaon Aeropyrum pernix K1 was studied. The experimental results indicate that APE1547 was one of the most stable hyperthermophilic enzymes. Its half-life was 20 h at 90 ℃(0.4 mg/mL), and it was stable in an alkalinous environment. At the same time, the change of the fluorescence and the activity was detected when the enzyme was thermally denatured. With the exposure of hydrophobic amino acids, its activity reduced gradually. Furthermore, this enzyme has a good pH stability and shows a good organic solvents resistance. The present results indicate that this enzyme will be useful in specific industry process such as high temperature or organic reaction.

Key words: Archeaon, Hyperthermophilic esterase, Thermostability, Aeropyrum pernix K1