Evolution is generally regarded as pretty good at specializing species for certain ecological niches, but with a glacial pace of adaptation, sometimes it needs a helping hand. Meet the team of the Weizmann Institute of Science in Israel, who decided they wanted to beef up the paraoxonase 1 (PON1) to the point it could combat sarin and other G-type nerve agents.
PON1 is an enzyme that is produced by our livers that can counteract sarin, tabun, soman, and cyclosarin, but not well enough for use in case of emergency — requiring people to use masks and suits, which can be penetrated. So the researchers undertook a path of "directed enzyme evolution," intentionally speeding up the course of adaptation to further their goal.
This technique is, essentially, the sort of wonderful mad science that we love here at io9. They artificially induced mutations into the gene that encoded target enzyme, creating variations in its efficiency and ability, and picking the best out of the lot. Within four generations of this process, the enzyme was functioning 340 times more efficiently than its natural form.
The hope is that the modified enzyme will be able to given to people going into an area exposed to these nerve agents to protect them, as well as being used to fight those already subjected to it. It also shows that with some judicious use of mutations and population pressure, "directed evolution" can provide very speedy results.
Photo by dr_ed_needs_a_bicycle.
Evolved Stereoselective Hydrolases for Broad-Spectrum G-Type Nerve Agent Detoxification [Chemistry & Biology]