The Californian researchers are hoping to exploit the flip side of this process. Proteins that resist digestion often do so because they are folded too tightly for digestive enzymes to gain access. The researchers aim to tackle this problem using thioredoxin, a non-allergenic protein found in all living organisms that specifically targets chemical bonds that help hold proteins in their folded shapes. Breaking these bonds allows proteins to unravel and so makes them easier to digest, and the researchers have shown that as a consequence, adding thioredoxin to wheat protein makes it less allergenic in animal tests. Since thioredoxin occurs naturally in seeds, where it accelerates the breakdown of proteins to provide amino acids for the growing seedling, the team reasoned that increasing the thioredoxin content of wheat grains should make them less allergenic.
Glutens are a large group of proteins that collectively allow wheat flour to form dough.
Unfortunately, a class of gluten proteins called gliadins cause intestinal damage in people with gluten intolerance, leading to symptoms such as chronic diarrhoea, weight loss and anaemia. The researchers are not yet testing the effects of thioredoxin-enrichment on gluten intoler ance. Since there is no animal model for the condition, such tests would require gluten-intolerant volunteers. B uchanan and his colleagues have other allergy targets, including soy beans and peanuts. In a paper just published, for example, they have shown that thioredoxin acts on two of the major allergenic proteins in peanuts.