<P> The 100 - petaFLOP distributed computing project Folding@home created by Vijay Pande's group at Stanford University simulates protein folding using the idle processing time of CPUs and GPUs of personal computers from volunteers . The project aims to understand protein misfolding and accelerate drug design for disease research . </P> <P> Long continuous - trajectory simulations have been performed on Anton, a massively parallel supercomputer designed and built around custom ASICs and interconnects by D.E. Shaw Research . The longest published result of a simulation performed using Anton is a 2.936 millisecond simulation of NTL9 at 355 K . </P> <P> While inferences about protein folding can be made through mutation studies, typically, experimental techniques for studying protein folding rely on the gradual unfolding or folding of proteins and observing conformational changes using standard non-crystallographic techniques . </P> <P> X-ray crystallography is one of the more efficient and important methods for attempting to decipher the three dimensional configuration of a folded protein . To be able to conduct X-ray crystallography, the protein under investigation must be located inside a crystal lattice . To place a protein inside a crystal lattice, one must have a suitable solvent for crystallization, obtain a pure protein at supersaturated levels in solution, and precipitate the crystals in solution . Once a protein is crystallized, x-ray beams can be concentrated through the crystal lattice which would diffract the beams or shoot them outwards in various directions . These exiting beams are correlated to the specific three - dimensional configuration of the protein enclosed within . The x-rays specifically interact with the electron clouds surrounding the individual atoms within the protein crystal lattice and produce a discernible diffraction pattern . Only by relating the electron density clouds with the amplitude of the x-rays can this pattern be read and lead to assumptions of the phases or phase angles involved that complicate this method . Without the relation established through a mathematical basis known as Fourier transform, the "phase problem" would render predicting the diffraction patterns very difficult . Emerging methods like multiple isomorphous replacement use the presence of a heavy metal ion to diffract the x-rays into a more predictable manner, reducing the number of variables involved and resolving the phase problem . </P>

How long does it take a protein to fold