Disulfide bonds, found in many proteins as well as in certain innovative materials, can adopt two “mirror-image” geometries. By reexamining previously described molecular structures and comparing them with theoretical calculations, scientists have shown that weak interactions between neighboring atoms are sufficient to guide this orientation. This research, published in the journal Chemical Communications, opens up new possibilities for finely controlling the properties of molecules or materials.

Disulfide bridges—C-S-S-C—are covalent bonds linking two sulfur atoms. In living systems, they play a role in the folding of many proteins and often determine their stability or biological activity. They are also found in self-healing polymers, adaptive materials, and molecular architectures capable of self-assembly.

Contrary to what its schematic representation might suggest, a disulfide bridge does not involve straight bonds. The two sulfur atoms spontaneously adopt a twisted geometry: when viewed along the axis of the bond, the two ends appear to coil either clockwise or counterclockwise, like a right-handed and a left-handed helix, respectively.

This property, known as axial chirality, most often influences the way a protein folds or the way a molecule interacts with its environment. Hence the importance of identifying the mechanisms—which are still poorly understood—that determine the preferential formation of one or the other of these two forms.

Read more on the CNRS website

Reference
Titouan Chetot, Adrien Forot, Elise Dumont, Florent Perret, Laurent Vial & Julien Leclaire, « The non-covalent stereocontrol of disulfide bonds », Chem. Commun. 2026, 62, 12723–12735. DOI