Nicotine-Eating Bacteria Could One Day Help Smokers Quit

People who smoke cigarettes know it’s bad for their health, but quitting is difficult. To make it easier, scientists are taking a novel approach – they are turning to microorganisms that thrive on nicotine. In a new paper published in the Journal of the American Chemical Society, researchers describe successful tests on a nicotine-degrading enzyme from a common soil bacterium called Pseudomonas putida.

Dr Janda’s team analyzed a nicotine-degrading enzyme, NicA2. Image credit: Song Xue et al.

Cigarette smoking is responsible for more than 480,000 deaths per year in the U.S., including nearly 42,000 deaths resulting from secondhand smoke exposure. If smoking continues at the current rate among U.S. youth, 5.6 million of today’s Americans younger than 18 years of age are expected to die prematurely from a smoking-related illness.

Smokers who want to quit can turn to various pharmacological aids. These include patches, gum and other nicotine-releasing products designed to replace cigarettes, as well as drugs that sequester nicotine in the body to prevent it from reaching the brain, where its addictiveness takes hold.

But the success rates of these options are low. Only 15 to 30% of smokers who try them are able to stop smoking for longer than one year.

Dr Kim Janda from the Scripps Research Institute and his colleagues wanted to try a new angle.

They used an enzyme called NicA2 that comes from Pseudomonas putida, a kind of bacteria already known to degrade tobacco waste.

In their experiments, NicA2, a flavin-containing protein, broke down all the nicotine in blood samples within 30 minutes.

It also remained stable for more than three weeks in a buffer solution, at least three days in serum, and mice given the enzyme showed no observable side effects.

“We have examined NicA2 that can catabolize nicotine to a non-addictive substance, 4-(methylamino)-1-(pyridin-3-yl) butan-1-one,” Dr Janda and co-authors wrote in the paper.

“We have conducted a kinetic profile on the enzyme and have found it has many qualities that would be desirable for a therapeutic utilization in smoking cessation, or nicotine intoxication.”

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Song Xue et al. A New Strategy for Smoking Cessation: Characterization of a Bacterial Enzyme for the Degradation of Nicotine. J. Am. Chem. Soc, published online August 3, 2015; doi: 10.1021/jacs.5b06605