Unusual Directionality in Thioamide Hydrogen Bonds Can Stabilize β-Strands

Though thioamides are considered weaker hydrogen-bond acceptors than oxoamides, recent calculations suggest they might enhance hydrogen bonds within the backbone of individual β-strands. We confirm this prediction through spectroscopic analysis of minimal amino-acid models. Further, incorporation of thioamides into the backbone of β-hairpin models high-lights opportunities to control β-strand stability.