Molecules programmed to fold into a triple helix, in the lab

Inside every living cell, proteins fold into precise shapes, and the instructions for each fold are written in the order of their molecular building blocks. At the University of Jyväskylä in Finland, a team led by professor Fabien Cougnon has built artificial molecules that follow a similar logic. Their counterclockwise triple helix, three molecular strands winding around one another, forms on demand rather than by chance.

The trick lies in two layers of information. The first layer, carried by the aromatic backbone of the molecule, performs an initial selection and restricts the possible outcomes of the assembly to four types of helices. The second layer, carried by side chains attached to the molecule, then favors one specific helix among those four. Each layer narrows the field, so that the final structure is selected rather than left to chance, and competing structures were effectively suppressed in the experiments.

Cougnon's team presents the result as a matter of careful design. "The key is that by fine-tuning the molecular sequence, we can precisely control which three-dimensional structure ultimately forms," he says. "We found that careful sequence optimization is crucial for achieving this high level of structural control." The work is laboratory research, published in Angewandte Chemie International Edition in 2026, and it shows control over a single type of molecular assembly rather than a finished material.

Replicating this kind of control in synthetic systems, where no cell does the sorting, has remained a major challenge, which is why the approach matters beyond this one molecule. For chemists who design new materials, a sequence that predictably produces a chosen shape is a tool that can be reused, and the study takes a step toward that goal. For the wider field, the question of when such molecules could appear in smart materials or molecular devices is left open: the authors name these uses as possibilities, and they give no date.