To determine the structure of rhodopsin, Krzysztof Palczewski, PhD, and his colleagues from Hyogo, Japan, first isolated the protein from cow retinas. Then, through a lot of trial and error, they found a bath with the precise blend of detergents, salt, and organic molecules to coax the protein to form crystals. Finally, they determined the structure by seeing how X-rays bounce off it. Meng, who coauthored an editorial that accompanied the paper, is a staff researcher in the department of cellular and molecular pharmacology at the University of California, San Francisco. The new snapshot should help researchers figure out how rod cells respond to light.
Light causes a shape change in rhodopsin, which sits on the surface of the cell.
He is a professor of chemistry, ophthalmology, and pharmacology at the University of Washington in Seattle. By understanding the details of how rhodopsin works, researchers could design drugs to treat some forms of retinitis pigmentosa, a disorder which leads to night blindness. That's because a mutant form of rhodopsin causes some forms of the disease, and a drug could help the mutant rhodopsin proteins act like normal ones. But the implications of the results go much further, Yeagle says. Other studies have shown that other GPCRs have a very similar shape to rhodopsin.