G-protein-coupled receptors (GPCRs) are among the protein target groups of the greatest importance for drug development. These receptors react to, for example, light, flavours, smells, adrenaline, histamine, dopamine and a long list of other molecules by transmitting further biochemical signals inside cells. The researchers who carried out the survey of GPCRs were rewarded with the Nobel Prize in Chemistry in 2012.
Today, roughly 30 per cent of all drugs on the market have GPCRs as their target proteins. Some drug molecules, such as morphine, activate the receptors (agonists) while others, such as beta blockers, inactivate them (antagonists).