Question: how long does it take a protein to fold

title: Protein folding
text: A fully denatured protein lacks both tertiary and secondary structure , and exists as a so - called random coil . Under certain conditions some proteins can refold ; however , in many cases , denaturation is irreversible . Cells sometimes protect their proteins against the denaturing influence of heat with enzymes known as heat shock proteins ( a type of chaperone ) , which assist other proteins both in folding and in remaining folded . Some proteins never fold in cells at all except with the assistance of chaperones which either isolate individual proteins so that their folding is not interrupted by interactions with other proteins or help to unfold misfolded proteins , allowing them to refold into the correct native structure . This function is crucial to prevent the risk of precipitation into insoluble amorphous aggregates . The external factors involved in protein denaturation or disruption of the native state include temperature , external fields ( electric , magnetic ) , molecular crowding , and even the limitation of space , which can have a big influence on the folding of proteins . High concentrations of solutes , extremes of pH , mechanical forces , and the presence of chemical denaturants can contribute to protein denaturation , as well . These individual factors are categorized together as stresses . Chaperones are shown to exist in increasing concentrations during times of cellular stress and help the proper folding of emerging proteins as well as denatured or misfolded ones .