Studying protein folding is a tedious activity that thousands of researchers around the world are working on. Forcing proteins to undergo their unique folding sequence is a difficult process, but now a technique developed at the University of Illinois, that uses rapid pressure changes to induce folding, should help speed up the process.
From a statement issued by University of Illinois:
To induce protein folding, a sample contained in a sapphire cube covered by a small steel diaphragm is pressurized to several thousand atmospheres, causing the biomolecules to unfold. A powerful electrical current then bursts the diaphragm, which releases the pressure and produces a sub-microsecond pressure drop. The proteins re-fold, and are monitored through laser-excited fluorescence.
Gruebele’s electrical-bursting method also allowed for a miniaturization of the apparatus, which improved the speed and sample volume of the diaphragm design. That, in turn, allows for a better comparison between how proteins fold in vitro in the lab versus how a computer algorithm would predict how they would fold.
After the pressure is applied, the proteins were able to re-fold or “spring back” to their native-state structures “much more readily than if we had heated them and cooled them down,” Gruebele said.
Applying pressure to induce protein folding is not a novel laboratory technique. According to Gruebele, previous methods using electrically controlled valves, piezoelectric constriction and burst diaphragms weren’t fast enough or didn’t produce enough pressure to generate viable data on the microsecond timescale.
To reach the realm of simulation-worthy data, “you need hundreds of nanoseconds to a few microseconds worth of data-capture time,” Gruebele said. With the previous methods, “we weren’t close to the timeframe where you could perform computer simulations, right now or in the near future.”