SUBMILLISECOND KINETICS OF PROTEIN-FOLDING

New experimental methods permit observation of protein folding and unf olding on the previously inaccessible nanosecond-microsecond timescale . These studies are beginning to establish times for the elementary mo tions in protein folding - secondary structure and loop formation, loc al hydrophobic collapse, and global collapse to the compact denatured state. They permit an estimate of about one microsecond for the shorte st time in which a protein can possibly fold.