Scientists reveal the secrets of how our mouths can taste bitterness. A new study describes the structure of an important bitter taste receptor and finds evidence that cholesterol appears to play an important role in supporting this receptor function.
Bitterness is one of the five basic tastes that humans can detect, along with sour, sweet, salty and umami (a meaty, savory taste). It was already known that our sense of bitter taste is largely controlled by certain receptors in our tongue and mouth known as type 2 taste receptors, or TAS2Rs. Of these receptors, TAS2R14 is particularly important because it can identify over 100 substances that impart a bitter taste.
The new research was led by scientists at the University of North Carolina School of Medicine, who decided to take a much closer look at TAS2R14 than ever before. Their findings were published Wednesday in the journal Nature.
“Scientists know very little about the structural makeup of sweet, bitter and umami taste receptors,” said study author Yoojoong Kim, a pharmacologist and postdoctoral fellow at UNC, in a opinion from the university. “Through a combination of biochemical and computational methods, we now know the structure of the bitter taste receptor TAS2R14 and the mechanisms that trigger the bitter taste sensation on our tongue.”
As is often the case with basic research of this kind, the researchers discovered some unexpected things. For example, they found cholesterol within a binding site – the region of a molecule where it can bind to another molecule – of the TAS2R14 receptor. This site was found next to another site that was supposed to be activated by a certain bitter, taste-inducing substance. The researchers suspect that cholesterol primes TAS2R14 to be easily activated by this substance, although it may also have other functions.
While the team’s work has helped scientists better understand a crucial aspect of our sense of taste, it also sets the stage for future research. Based on their findings, it is possible that TAS2R14 has other functions besides simply assisting with the taste of bitter foods.
Other taste research has produced some interesting results, such as: Why fat tastes so good. In 2021, Gizmodo asked experts if Technology might ever be able to improve our sense of taste. “Molecular receptors have now been identified for all five basic tastes,” a researcher told us at the time. “These can and are used to fish out compounds that increase or decrease their activity, leading to, for example, the identification of sweet enhancers or bitter blockers that can be added to foods or medicines.”