Folding of a miniprotein with mixed fold Available to Purchase

Using the 28 residue $ββα$ protein FSD-EY as a target system, we examine correction terms for the ECEPP/3 force field. We find an increased probability of formation of the native state at low temperatures resulting from a reduced propensity to form $α$ helices and increased formation of $β$ sheets. Our analysis of the observed folding events suggests that the $C$-terminal helix of FSD-EY is much more stable than the $N$-terminal $β$ hairpin and forms first. The hydrophobic groups of the helix provide a template which promotes the formation of the $β$ hairpin that is never observed to form without the helix.