Can toxic mushrooms make drugs more precise?

Working Amanita mushrooms, the team disassembled one of its poisonous peptides, which can be compared to a laser-guided missile with a nuclear warhead. (Credit: Amanita bisporigera by Dan Molter/Mushroom Observer via Wikimedia Commons)

Scientists have discovered an enzyme that’s key to the killing power of poisonous mushrooms.

The new findings reveal the enzyme’s ability to create the mushroom’s molecules that harbor missile-like proficiency in attacking and annihilating a single vulnerable target in the human liver.

The study, available in the journal Chemistry and Biology, reveals how the enzyme contributes to the manufacture of chemical compounds known as cyclic peptides, a favorite type of molecule that pharmaceutical companies use to create new drugs.


These findings could lead to single-minded medicines with zero side effects, says co-lead author Jonathan Walton, professor of plant biology at Michigan State University.

“Mushrooms are prolific chemical factories, yet only a few of their peptides are poisonous,” he says. “These toxins survive the high temperatures of cooking and the acids of digestion, and yet they’re readily absorbed by the bloodstream and go directly to their intended target. These are the exact qualities needed for an effective medicine.”

Working Amanita mushrooms, Walton and colleagues disassembled one of its poisonous peptides, which can be compared to a laser-guided missile with a nuclear warhead.

By removing the molecular equivalent of the deadly warhead, they now have a sturdy, precise delivery system that can supply medicine—rather than poison—to a single target. By taking a laser, rather than a shotgun approach, scientists could develop medicines capable of curing disease without the patient suffering any side effects.

The enzyme the team discovered is called POPB, and it converts toxins from their initial linear shape into cyclic peptides, fortress-like molecular circles comprising eight amino acids.

Harnessing the distinct properties of POPB will allow scientist to create billions of variant molecules, which can be tested against many different medical targets such as pathogenic bacteria and cancer.

“We’ve found some variables that are key,” says Walton. “By making more variants, we can add or replace molecules that may or may not work. To date we’ve created a library of a hundred or so, and we eventually plan to create millions.”

The challenge of the next stage of research, though, is testing the variants against diseases such as cancer. The bottleneck lies in the screening process. While Walton’s team has discovered a missile capable of carrying a million different potential medicines, as of yet the payload that will be effective remains a mystery.

Additional researchers at Michigan State and the Kunming University of Science and Technology in China, also contributed to the paper.

The National Institutes of Health funds Walton’s research.

Source: Michigan State University