Creating a material that surpasses both steel in strength and rubber in flexibility: this feat is performed daily by spiders when they produce their silk. For many years, the molecular mechanism behind these extraordinary properties remained poorly understood.
An international team now provides answers by examining interactions between specific amino acids. Their work, published in
Proceedings of the National Academy of Sciences, illustrates how elementary principles allow nature to develop structures with exceptional qualities.
The mechanism relies mainly on two amino acids, arginine and tyrosine. Their particularity is to attract and bind to each other in a reversible way, like molecular stickers. This attraction gradually guides the assembly of proteins, transforming a viscous solution into a solid and structured filament. This process explains silk's unique ability to combine high load-bearing strength with notable elasticity, a rare combination.
This breakthrough opens up interesting possibilities in the field of materials. By drawing inspiration from these natural rules, the design of innovative fibers becomes conceivable. For example, lighter protective clothing, more durable aerospace components, or even biodegradable medical implants could emerge. These advances could also lead to a reduction in the environmental impact of certain industrial processes.
Surprisingly, these molecular interactions show similarities with mechanisms at work in the human body. They are involved, among other things, in communication between neurons and could help us understand certain neurodegenerative diseases, such as Alzheimer's. Thus, the study of silk provides a useful model for medical research, offering a simplified system to analyze more general biological phenomena.
By decoding spiders' strategies, scientists are not only seeking to imitate nature. They are learning to exploit its principles to innovate in many fields, from materials engineering to fundamental biology. This approach facilitates the development of more efficient and sustainable technologies, benefiting from the optimization carried out by evolution over time.