A couple of years ago, I told you about Foldit, a computer game that harnesses the power of human putzing to help scientists unravel the mysteries of protein structure. There's a new research paper out that uses results from Foldit as a basis for a new proposed structure of a key protein in a virus that is a relative of HIV.
As important as proteins are, we know relatively little about how and why these complex chains of amino acids fold and twist the way they do and how that structure relates to function. Foldit takes advantage of the fact that, given the right rules, people can come up with possible, plausible protein structures far faster than a computer program can factor out all the possible permutations. And that's why Foldit players—citizen scientists of a sort—were so useful in this case. Ed Yong at Not Exactly Rocket Science explains:
They discovered the structure of a protein belonging to the Mason-Pfizer monkey virus (M-PMV), a close relative of HIV that causes AIDS in monkeys. These viruses create many of their proteins in one big block. They need to be cut apart, and the viruses use a scissor enzyme –a protease – to do that. Many scientists are trying to find drugs that disable the proteases. If they don’t work, the virus is hobbled – it’s like a mechanic that cannot remove any of her tools from their box.
To disable M-PMV’s protease, we need to know exactly what it looks like. Like real scissors, the proteases come in two halves that need to lock together in order to work. If we knew where the halves joined together, we could create drugs that prevent them from uniting. But until now, scientists have only been able to discern the structure of the two halves together. They have spent more than ten years trying to solve structure of a single isolated half, without any success.
The Foldit players had no such problems. They came up with several answers, one of which was almost close to perfect. In a few days, Khatib had refined their solution to deduce the protein’s final structure, and he has already spotted features that could make attractive targets for new drugs.
“This is the first instance that we are aware of in which online gamers solved a longstanding scientific problem,” writes Khatib. “These results indicate the potential for integrating video games into the real-world scientific process: the ingenuity of game players is a formidable force that, if properly directed, can be used to solve a wide range of scientific problems.”