So the researchers attempted to reproduce the same effects using a synthetic catalyst. Sciencedescribes nicely how they went about the process:
They started with metal-organic frameworks (MOFs), a recently developed class of porous compounds composed of metals arranged in a crystalline network linked by carbon-based molecules. MOFs are highly adaptable materials... and because MOFs are porous, they have large surface areas that can rapidly create chemical bonds, making them good candidates for catalysts.
In the natural enzyme, phosphotriesterase, two zinc atoms act as so-called Lewis acids, which accept electrons to bind with the nerve agent. Once the agent has bonded, hydrolysis occurs—a water molecule attacks the agent, slicing and dicing essential chemical bonds, thereby deactivating it. The scientists designed a MOF with a similar structure, but they replaced the zinc with zirconium, which likewise behaves as a Lewis acid and makes for an ultrastable MOF.
In tests published in Nature Materials, the team used their catalyst to deactivate a pesticidesimilar to nerve agents but safer to use in the lab. Experiments showed that the new compounds—known as NU-1000—deactivated half of the pesticide in 15 minutes. Further testing by U.S army facilities has shown that it neutralizes half of the nerve agent GD—more toxic than the well-known sarin—in just three minutes. The researchers claim that that's 80 times faster than any previous compound has managed.
It's still not perfect, though. Indeed, the natural version—though fragile—works up to 100,000 times faster, so the team certainly has some way to go before it's as good as nature itself. But for now, it's a significant milestone in the quest to keep the world safe from chemical warfare.
source: gizmodo.com by Jamie Condliffe