Poppy pods from the plant Papaver somniferum—the source of many opiates, including morphine and codeine. Researchers recently published the high-resolution structures of two of the body's opioid receptors. FLICKR, TRENARREN
Opioid receptors revealed
Name: Kappa-opioid receptor (?-OR) and mu-opioid receptor (µ-OR)
The brain’s opioid receptors regulate powerful neurological effects such as sedation, analgesia, depression, and euphoria by serving as the targets of a wide range of endogenous molecules such as endorphins and opiate drugs like morphine, codeine, oxycodone, and heroin. Although their detailed atomic structures have been highly sought after for decades, these cell membrane proteins have long evaded X-ray crystallography—a process that requires them to be purified in high quantities and then crystallized before their structures can be illuminated by X-ray crystallography. Now two independent research teams have produced high-resolution atomic structures of the mu-opioid receptor (µ-OR), which recognizes morphine and codeine, and the kappa-opioid receptor (?-OR), the only known receptor for Salvinorin A, ...
