New study shows that the way amyloid proteins—implicated in Alzheimer’s disease—assemble into fibrils can be significantly influenced by the spin orientation of electrons on magnetized surfaces. Depending on the direction of the magnetization and the chirality of the protein building blocks, the researchers observed major differences in the number, length, and structure of the resulting fibrils. These findings suggest that electron spin, through a mechanism known as Chiral-Induced Spin Selectivity (CISS), plays a direct role in protein self-assembly, pointing to a new and previously overlooked physical factor that could be harnessed to control or interfere with amyloid formation in neurodegenerative diseases.

A new study has found that the magnetic orientation of a surface can significantly affect the way certain proteins—specifically those associated with Alzheimer’s disease—assemble into larger structures. The results suggest that a physical property known as electron spin may influence biological self-assembly, with potential implications for understanding and possibly intervening in neurodegenerative conditions.
The study was published this week in ACS Nano and led by Yael Kapon, a PhD student at the Hebrew University of Jerusalem’s Institute of Applied Physics, under the guidance of Prof. Yossi Paltiel and in collaboration with Prof. Ehud Gazit from Tel Aviv University.

Magnetic Fields and Amyloid Fibrils

At the center of the research is amyloid-beta (Aβ₁–₄₂), a short peptide that is known to form sticky fibrils and plaques in the brains of people with Alzheimer’s disease. Using magnetized surfaces, the team investigated how these peptides aggregate and whether the spin orientation of the substrate—essentially, the direction in which the electrons are aligned—could affect the process.

The results were striking. When the magnetization of the surface was aligned in one direction, the amyloid proteins formed nearly twice as many fibrils, some up to 20 times longer, compared to when the magnetization was reversed. The pattern also flipped when the researchers used a version of the peptide with opposite chirality (or molecular "handedness"), indicating a strong spin-dependent effect.

These behaviors are consistent with a phenomenon known as Chiral-Induced Spin Selectivity (CISS), in which chiral (asymmetric) molecules interact differently with electrons depending on their spin. While this effect has been studied in chemistry and materials science, it has only recently begun to be explored in biological systems.

Understanding the Role of Spin in Biology
The study’s authors believe that the interplay between molecular chirality and electron spin could play a previously underappreciated role in protein self-assembly. Using techniques such as electron microscopy and infrared spectroscopy, they also found that the resulting amyloid structures varied not just in size and quantity, but in their underlying molecular arrangement—again depending on the direction of magnetization.

“We’re beginning to see that biology may be more sensitive to spin than we thought,” said Prof. Yossi Paltiel of the Hebrew University. “Our work shows that spin-related forces can directly influence the way proteins aggregate. That’s a new dimension to consider when thinking about diseases like Alzheimer’s, which involve the buildup of these kinds of fibrils.”

Prof. Ehud Gazit, a leading expert in protein self-assembly at Tel Aviv University, added:
“These findings add a new layer to our understanding of amyloid formation. They suggest that physical properties like electron spin—not just biochemical interactions—can play a meaningful role in how these harmful structures develop. This opens up new possibilities for designing technologies that influence protein behavior in targeted and non-invasive ways.”

Looking Ahead: Applications and Possibilities
While the findings are still in the realm of basic research, they point to new ways of thinking about how to control unwanted protein aggregation. The team suggests that magnetized or spin-polarized materials—such as specially designed nanoparticles or filtration membranes—could one day be used to selectively influence or interrupt the formation of harmful amyloid structures. Such technologies might find applications not only in treating neurodegenerative diseases, but also in addressing amyloidosis linked to dialysis and other medical conditions.

“This study gives us a new tool to probe how proteins come together,” said Kapon. “We hope it will help guide future research into how to slow, prevent, or redirect these processes in a controlled way.”
The research adds to a growing body of work exploring how physical properties—beyond chemical interactions—can influence biological behavior. It also highlights the value of interdisciplinary collaboration, bringing together physics, chemistry, and biomedicine.