An enzyme from a bacterium that lives on tobacco plants may be the key to a new type of "vaccine" to help smokers quit
Quitting smoking is tough—so tough that only about 5 percent of smokers who try to quit in a given year actually succeed. Medications can double those odds—which still leaves a high failure rate. And a promising vaccine, meant to arouse an immune response to nicotine, could not beat a placebo in clinical trials. But researchers haven't given up on a vaccine yet. Instead of revving up the immune system, though, they've come up with a new idea: Why not use an enzyme to break down nicotine—before it gives you a buzz?
This is Scientific American’s 60-Second Science. I’m Christopher Intagliata. Got a minute?
"For almost 50 years there's been reports of bacteria that can actually use nicotine to thrive on," [says] Kim Janda, a chemist and immunologist at The Scripps Research Institute. "The bacteria uses nicotine as its sole source of carbon and nitrogen."
It does the trick with a nicotine-chomping enzyme. So Janda and his colleagues added the enzyme to mouse serum, doped with a cigarette's worth of nicotine. The enzyme was stable at human body temperature—and was able to cut the half-life of nicotine from a couple hours to less than 15 minutes—that is, it greatly accelerated nicotine’s disappearance. The study is in the Journal of the American Chemical Society. [Song Xue et al, A New Strategy for Smoking Cessation: Characterization of a Bacterial Enzyme for the Degradation of Nicotine]
But Janda says the enzyme isn't ready for prime time yet. It's bacterial—so "you're going to get an immune response, immune surveillance from it." And right now the other important half-life, that of the enzyme in serum, is only three days. So it won’t stick around long enough to be an effective vaccine. "A month would be great, a week or two would also be reasonable." While the researchers work out the kinks, smokers will have to rely on the tried-and-true methods of quitting: counseling, medication or good old cold turkey.
Thanks for the minute! For Scientific American’s 60-Second Science, I’m Christopher Intagliata.
[The above text is a transcript of this video.]
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Executive Producer: Eliene Augenbraun
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Writer and Narrator: Christopher Intagliata
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Special Thanks: Kim Janda
Journal title page reproduced in part with permission from J. Am. Chem. Soc. 2015, 137(32), 10136–10139. Copyright 2015 American Chemical Society