Inhabiting the soil near the coca plant is a bacterial enzyme with exciting possibilities for the world of rehabilitative medicine. Cocaine esterase, as the enzyme is called, helps neutralize the effects of cocaine in the bloodstream by breaking the drug into tiny little bits; scientists think it could be used one day to help addicts get clean, or to stop an overdose in progress.
The downside is that its shelf life is woefully short—too short to do any good. Once isolated from the bacteria, cocaine esterase becomes unstable, and can only live in the bloodstream for about 12 minutes. Scientists say that in order to be effective as an addiction treatment, it would need to chop up cocaine for days at a time.
Now for the first time, researchers have successfully tweaked the enzyme to make it more stable and long-lasting. Using computer modeling, Chang-Guo Zhan at the University of Kentucky and his team identified which parts of cocaine esterase were the first to degrade under rising temperatures. After experimenting with various genetic tweaks, they found they needed just two mutations to make the weak areas more stable.
To test the altered version of the enzyme, the scientists injected it into mice—followed by a lethal dose of cocaine. The mice survived.
All told, the team was able to stabilize the enzyme to last 94 hours in a mouse's bloodstream—long enough, the scientists hope, to one day treat addiction as well as overdose.
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