Gamers set sights on neutralizing aflatoxin

Foldit is a multiplayer online puzzle game developed at the University of Washington.

It allows users to explore how amino acids are folded together to create proteins by putting proteins online and allowing users to manipulate their structures.

The puzzles provide gamers with a starting enzyme that has the potential to degrade aflatoxin. Gamers then attempt to redesign and improve it to neutralize aflatoxin. To play the Foldit game go here: https://fold.it​.​

Decrease aflatoxin toxicity​

Foldit will be used to create an enzyme to attack aflatoxins at a vulnerable point - a part of their molecular structure known as a lactone ring. Breaking this ring will decrease toxicity by several orders of magnitude and should render it non-toxic.

Top designs will be synthesized using synthetic biology techniques and materials donated by Thermo Fisher Scientific. They will then be tested at labs in UC Davis for their real world potential to eradicate aflatoxin.

Dr Howard-Yana Shapiro, chief agricultural officer at Mars and Professor Justin Siegel, professor, department of biochemistry, chemistry and the genome at UC Davis said the game can almost be thought of like a three-dimensional Tetris.

“The underlying reason we are using enzymes to degrade aflatoxin as opposed to a broader spectrum decontamination approach is that it enables us to specifically degrade the toxin without effecting the rest of the food,” ​they said. ​

“Unfortunately, that specificity also means that a unique enzyme is needed for each mycotoxin as they are all vastly different in chemical structure. So while we are starting off with the aflatoxin family, there are definite plans to move forward and utilize this strategy on many other mycotoxins.”​

Foldit was released in May 2008 and has had successes. For example, in 2011 a dozen gamers took 10 days to unravel the structure of an enzyme involved in a virus similar to HIV – a problem that had troubled scientists for decades.

Results in two to three months​

The collaboration is between Thermo, the Partnership for Aflatoxin Control in Africa (PACA), the University of California, Davis, the University of Washington, Northeastern University and Mars.

Aflatoxin is a mycotoxin - chemical compounds produced by fungal moulds that grow on raw materials and the FAO estimates that a quarter of food crops are contaminated.

Environmental conditions such as drought and rising temperatures have triggered an upsurge in toxic crops with climate change increasing the prevalence of aflatoxin.

Toxins also accumulate during postharvest storage and handling of produce with higher moisture levels.​

The game stays live for two to three weeks and the shapes and structures players create are collected.

“Once we have those – because of the technology that Thermo Fisher Scientific is bringing to the table – they will synthesize hundreds if not thousands of genes that correspond to the players’ designs. That’ll be done within just a few weeks,” ​said Dr Shapiro and Professor Siegel.​

“Using these genes, researchers in the Siegel Lab at UC Davis will then determine whether the genes are capable of degrading Aflatoxin B1, the type of aflatoxin that is most carcinogenic. ​

“So from the first time the puzzle’s posted to when we’re expecting the first results is on the order of two to three months.”​

Cleaning and optical sorting methods​

Helge Bastian, VP and general manager of synthetic biology at Thermo Fisher Scientific, said it was excited to address a major health issue. ​

“Biology runs on a digital code, DNA - the software of life, that we can now design, write, modify and manufacture to engineer more effective, scalable solutions to real-world problems. This project has the potential to demonstrate the power of synthetic biology as a key discipline for a sustainable future.” ​

Dr Shapiro and Professor Siegel said cleaning methods are unable to get rid of the toxin due to the extremely low levels needed for products to be considered aflatoxin free.

“In addition, the current cleaning methods that don’t compromise the food leave you with a highly concentrated pool of toxic media which is difficult to dispose of in an environmentally friendly manner,” ​they said.​

“Optical sorting methods have issues which also result in a highly toxic stockpile for the product removed. Though, the use of specific catalysts that selectively destroys the toxin without compromising the nutrition or flavor of the food products should greatly enhance efficacy of modern cleaning and sorting methods.”​