Original Paper

Extremophiles

, Volume 9, Issue 4, pp 297-305

A thermostable phosphotriesterase from the archaeon Sulfolobus solfataricus: cloning, overexpression and properties

  • Luigia MeroneAffiliated withIstituto di Biochimica delle Proteine, Consiglio Nazionale delle Ricerche
  • , Luigi MandrichAffiliated withIstituto di Biochimica delle Proteine, Consiglio Nazionale delle Ricerche
  • , Mosè RossiAffiliated withIstituto di Biochimica delle Proteine, Consiglio Nazionale delle Ricerche
  • , Giuseppe MancoAffiliated withIstituto di Biochimica delle Proteine, Consiglio Nazionale delle Ricerche Email author 

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

A new gene from the hyperthermophilic archaeon Sulfolobus solfataricus MT4, coding for a putative protein reported to show sequence identity with the phosphotriesterase-related protein family (PHP), was cloned by means of the polymerase chain reaction from the S. solfataricus genomic DNA. In order to analyse the biochemical properties of the protein an overexpression system in Escherichia coli was established. The recombinant protein, expressed in soluble form at 5 mg/l of E. coli culture, was purified to homogeneity and characterized. In contrast with its mesophilic E. coli counterpart that was devoid of any tested activity, the S. solfataricus enzyme was demonstrated to have a low paraoxonase activity. This activity was dependent from metal cations with Co2+, Mg2+ and Ni2+ being the most effective and was thermophilic and thermostable. The enzyme was inactivated with EDTA and o-phenantroline. A reported inhibitor for Pseudomonas putida phosphotriesterase (PTE) had no effect on the S. solfataricus paraoxonase. The importance of a stable paraoxonase for detoxification of chemical warfare agents and agricultural pesticides will be discussed.

Keywords

Phosphotriesterase Organophosphates Pesticides Sulfolobus solfataricus Thermostability