Extremophiles

, Volume 13, Issue 3, pp 461–470

Structural determinants of the high thermal stability of SsoPox from the hyperthermophilic archaeon Sulfolobus solfataricus

  • Pompea Del Vecchio
  • Mikael Elias
  • Luigia Merone
  • Giuseppe Graziano
  • Jérôme Dupuy
  • Luigi Mandrich
  • Paola Carullo
  • Bertrand Fournier
  • Daniel Rochu
  • Mosè Rossi
  • Patrick Masson
  • Eric Chabriere
  • Giuseppe Manco
Original Paper

DOI: 10.1007/s00792-009-0231-9

Cite this article as:
Del Vecchio, P., Elias, M., Merone, L. et al. Extremophiles (2009) 13: 461. doi:10.1007/s00792-009-0231-9

Abstract

Organophosphates (OPs) constitute the largest class of insecticides used worldwide and certain of them are potent nerve agents. Consequently, enzymes degrading OPs are of paramount interest, as they could be used as bioscavengers and biodecontaminants. Looking for a stable OPs catalyst, able to support industrial process constraints, a hyperthermophilic phosphotriesterase (PTE) (SsoPox) was isolated from the archaeon Sulfolobus solfataricus and was found to be highly thermostable. The solved 3D structure revealed that SsoPox is a noncovalent dimer, with lactonase activity against “quorum sensing signals”, and therefore could represent also a potential weapon against certain pathogens. The structural basis of the high thermostability of SsoPox has been investigated by performing a careful comparison between its structure and that of two mesophilic PTEs from Pseudomonas diminuta and Agrobacterium radiobacter. In addition, the conformational stability of SsoPox against the denaturing action of temperature and GuHCl has been determined by means of circular dichroism and fluorescence measurements. The data suggest that the two fundamental differences between SsoPox and the mesophilic counterparts are: (a) a larger number of surface salt bridges, also involved in complex networks; (b) a tighter quaternary structure due to an optimization of the interactions at the interface between the two monomers.

Keywords

Hyperthermophilic enzyme Conformational stability Salt bridges Quaternary structure organization 

Abbreviations

OPs

Organophosphates

PTE

Phosphotriesterase

OPD

Organophosphate-degrading

PLL

Phosphotriesterase-like lactonase

Copyright information

© Springer 2009

Authors and Affiliations

  • Pompea Del Vecchio
    • 1
  • Mikael Elias
    • 2
  • Luigia Merone
    • 3
  • Giuseppe Graziano
    • 4
  • Jérôme Dupuy
    • 5
  • Luigi Mandrich
    • 3
  • Paola Carullo
    • 1
  • Bertrand Fournier
    • 6
  • Daniel Rochu
    • 7
  • Mosè Rossi
    • 3
  • Patrick Masson
    • 7
  • Eric Chabriere
    • 2
    • 7
  • Giuseppe Manco
    • 3
  1. 1.Dipartimento di Chimica “Paolo Corradini”Università di Napoli “Federico II”NaplesItaly
  2. 2.Architecture et Fonction des Macromolécules BiologiquesCNRS-Université de la MéditerranéeMarseilleFrance
  3. 3.Istituto di Biochimica delle Proteine, Consiglio Nazionale delle RicercheNaplesItaly
  4. 4.Dipartimento di Scienze Biologiche ed AmbientaliUniversità del SannioBeneventoItaly
  5. 5.Laboratoire de Cristallogenèse et Cristallographie des ProtéinesInstitut de Biologie Structurale JP EBELGrenobleFrance
  6. 6.Laboratoire de Cristallographie et Modélisation des Matériaux Minéraux et BiologiquesCNRS-Université Henri PoincaréNancyFrance
  7. 7.Unité d’Enzymologie, Département de ToxicologieCentre de Recherches du Service de Santé des ArméesLa TroncheFrance

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