Periodic Reporting for period 4 - Microrobots (Engineering Biohybrid MicroRobots from Magnetic Swimmers and S-layers)
Periodo di rendicontazione: 2023-05-01 al 2024-12-31
Biotechnology harnesses the power of biological systems that have evolved over billions of years to create new solutions in areas such as chemical synthesis, medicine, and nanotechnology. Proteins - molecular machines that populate all cells and perform many crucial functions of life - are of key interest for biotechnology, as they can perform precision tasks at the nanoscale, beyond the capabilities of any human-made tools. However, proteins are often fragile and disintegrate outside their native cellular environment. The solution to this problem is the use of proteins from extremophilic microorganisms. These proteins are extremely stable because they have evolved to endure the harsh conditions that their host cells have evolved in, such as boiling temperatures, harsh acids, or extremely salty environments.
In this project, we investigated the structure and function of proteins generated by extremophilic archaea to inform the design of innovative nanotools for drug delivery. We focused on two special types of polymer-forming proteins: S-layer proteins that encapsulate and protect archaeal cells, and surface filaments with adhesive and motile functions. Informed by this research, we conceptualised and engineered innovative solutions for drug delivery and microrobotics.
In this project, we investigated the structure and function of proteins generated by extremophilic archaea to inform the design of innovative nanotools for drug delivery. We focused on two special types of polymer-forming proteins: S-layer proteins that encapsulate and protect archaeal cells, and surface filaments with adhesive and motile functions. Informed by this research, we conceptualised and engineered innovative solutions for drug delivery and microrobotics.
S-layers are two-dimensional crystalline lattices that coat microbial cells, providing protection and structural integrity. Using cryo-electron microscopy, investigated various archaeal and bacterial S-layers. Focusing on the S-layer of the archaeon Sulfolobus acidocaldarius, we determined its structure at high resolution and built an atomic model. Informed by this model, we introduced affinity tags into exposed glycan sites, enabling functionalisation with various ligands, and determined a chemical switch to trigger in vitro assembly and disassembly. This gave rise to "smart", pH-sensing nanocapsules for novel drug delivery solutions.
In parallel, we resolved the structures of six archaeal surface filaments: three archaella, two type IV pili, and a newly discovered filament we named the "thread." Archaella function as rotary nanomotors for swimming motility. By developing new cryoEM image processing tools, we advanced our understanding of these archaella and challenged prior models of their composition and dynamics, informing the development of bioinspired nanoproellers for microrobotics.
Among pili, we focused on the Aap filament, involved in twitching motility. Our data showed that Aap adopt a metastable triple-helix structure that spontaneously retract without energy input, which provide useful tools for microrobotic systems requiring autonomous actuation.
The thread filament is exceptionally stable, resistant to acid, heat, detergents, and enzymatic degradation. It assembles into cable-like bundles and features a linear chain of aromatic residues arranged in a geometry compatible with electron tunnelling. This makes the thread an attractive candidate for biodegradable nanowires usable in sustainable bioelectronics.
We disseminated our findings through open-access journals, preprints, media outreach, and public engagement events. Our research was widely presented by an eminent science YouTuber, reaching over 94,000 viewers. We also engaged with pharmaceutical companies to explore the translational potential of our encapsulation technology. Finally, our project enabled our co-creation and participation in a new Marie Skłodowska-Curie Doctoral Network called ArcTech, to train early-career researchers in archaeal biology and biotechnology.
In parallel, we resolved the structures of six archaeal surface filaments: three archaella, two type IV pili, and a newly discovered filament we named the "thread." Archaella function as rotary nanomotors for swimming motility. By developing new cryoEM image processing tools, we advanced our understanding of these archaella and challenged prior models of their composition and dynamics, informing the development of bioinspired nanoproellers for microrobotics.
Among pili, we focused on the Aap filament, involved in twitching motility. Our data showed that Aap adopt a metastable triple-helix structure that spontaneously retract without energy input, which provide useful tools for microrobotic systems requiring autonomous actuation.
The thread filament is exceptionally stable, resistant to acid, heat, detergents, and enzymatic degradation. It assembles into cable-like bundles and features a linear chain of aromatic residues arranged in a geometry compatible with electron tunnelling. This makes the thread an attractive candidate for biodegradable nanowires usable in sustainable bioelectronics.
We disseminated our findings through open-access journals, preprints, media outreach, and public engagement events. Our research was widely presented by an eminent science YouTuber, reaching over 94,000 viewers. We also engaged with pharmaceutical companies to explore the translational potential of our encapsulation technology. Finally, our project enabled our co-creation and participation in a new Marie Skłodowska-Curie Doctoral Network called ArcTech, to train early-career researchers in archaeal biology and biotechnology.
This ERC-funded research pushed the boundaries of archaeal and structural biology. We produced the first complete atomic model of a two-component archaeal S-layer and pioneered its engineering as a modular toolkit for innovative "smart" nanocapsules. We gained deeper insights into the structure and dynamics of archaella, via a newly developed helical reconstruction workflow, and revealed a potentially energy-independent actuation mechanism of the Aap filament. Our discovery of the thread introduced a new class of likely conductive, ultra-stable pilus with potential in bioelectronics. Together, these achievements provided innovative extremophile-inspired biotechnology solutions and laid the foundation for future innovations in nanomedicine, materials science, and synthetic biology.