A novel esterase Sso2518 from Sulfolobus solfataricus with a much lower temperature optimum than the growth temperature

Abstract

An esterase, Sso2518, from Sulfolobus solfataricus P2 was over-expressed in E. coli. and characterized after purification. The maximum activity was at pH 7.5 and 50 degrees C. The half life of Sso2518 was about 30 min at 85 degrees C and the enzyme was activated by Cu(2+). The catalytic triad of Sso2518 was comprised of residues Ser151, Asp176, and His328. Sso2518 showed the highest activity with p-nitrophenyl caproate (C6) and could also hydrolyze olive oil. Under native conditions, Sso2518 consists of 125 kDa homotrimers.