Related Experiment Video
Updated: Jun 10, 2026

A New Screening Method for the Directed Evolution of Thermostable Bacteriolytic Enzymes
Published on: November 7, 2012
Improving the promiscuous nerve agent hydrolase activity of a thermostable archaeal lactonase
Luigia Merone1, Luigi Mandrich, Elena Porzio
1Istituto di Biochimica delle Proteine, Consiglio Nazionale delle Ricerche, Via P. Castellino 111, 80131 Naples, Italy.
Abstract:
The thermostable Phosphotriesterase-Like Lactonase from Sulfolobus solfataricus (SsoPox) hydrolyzes lactones and, at a lower rate, neurotoxic organophosphorus compounds. The persistent demand of detoxification tools in the field of agricultural wastes and restoring of conditions after terrorist acts prompted us to exploit SsoPox as a "starter" to evolve its ancillary nerve agents hydrolytic capability. A directed evolution strategy yielded, among several variants, the single mutant W263F with k(cat) and specificity constant against paraoxon 16- and 6-fold enhanced, respectively, compared to the wild type. Furthermore, a phenomenon of enzyme activation by SDS has been observed, which allowed to increase those values 150- and 28-fold, respectively. The activity of SsoPox against the deadly nerve gas Cyclosarin has been reported for the first time and proved to be substantially unaffected for variant W263F. Finally, outperforming efficiency of W263F was demonstrated, under severe stressing conditions, with respect to the best known phosphotriesterase PTE from Brevundimonas diminuta.
Related Concept Videos
Diversity of Archaea III
Diversity of Archaea IV
Production of Organic Acids
Lysosomal Hydrolases
Hyperthermophilic Bacteria
Hydrolysis
Hydrolysis is a chemical reaction in which the addition of water breaks down a polymer into its simpler monomer units. For example, peptides break into amino acids, carbohydrates into simple sugars, and DNA into nucleotides. Enzymes often facilitate these processes.
Hydrolysis Reverses Dehydration Synthesis
Complex carbohydrates can be broken down by breaking the bonds between individual sugar units. The reaction breaks a glycosidic bond as water is added to the compound. The...

