Artificial active

Decoding protein assembly dynamics with artificial protein needles – sciencedaily

The assembly of proteins is essential for the formation of ordered biological structures, but imagine one! This is exactly what researchers at Tokyo Tech have now accomplished with protein needles. By regulating the tip-to-tip interactions of these needles, they enabled their self-assembly into lattice structures, ordered monomeric states, and fiber assemblies, paving the way for the controlled construction of several of these protein architectures.

Proteins are the building blocks of our body. However, their molecular and macroscopic structures are complex and varied, with multiple folding patterns and substructures. Scientists have been trying to decode these structures for some time, and many advances have been made using fluorescence microscopy (FM), atomic force microscopy (AFM), and high speed AFM (HS-AFM). . However, they were not able to directly observe the dynamic movements of proteins during assembly. This is mainly due to the complex structure of the proteins, which are too small to be measured with existing techniques.

A team of researchers from the Tokyo Institute of Technology (Tokyo Tech), Kyushu University, Nagoya University, and National Institutes of Natural Sciences have now developed a specialized anisotropic protein (PN) needle for help determine the assembly of similar anisotropic proteins, giving us clues about their microstructure and assembly.

Professor Takafumi Ueno of Tokyo Tech, who led the study, explains the premises of their work: “Our PN is a needle-shaped protein made up of the rigid body (β helix), end cap (foldon) and d ‘a motif bond (hexa-histidine tag, His tag). By modifying these PNs by removing the His-tag pattern and the flip-up cap, we can produce three different types of PN. This allowed us to regulate and observe different assembly patterns and how they change, giving us clues about the mechanics of the different protein-protein interactions that we find in nature. The results of this study were published in the journal Small.

In solution, PNs spontaneously form a very stable structure about 20 nm long and about 3.5 nm wide, small enough to follow the rotational movement of individual molecules while being mechanically strong.

On surfaces, the team observed different types of ordered structures as the PRs self-assembled. These structures ranged from triangular networks and monomer states with nematic order (one-dimensional orientation) to fiber assemblies.

This, in turn, allowed the team to study the dynamic processes involved in protein assembly through a combination of HS-AFM and simulations. The results revealed that the formation of the triangular lattice structure was guided by the dynamic movements of PN, which help to form ordered lattices.

These findings have excited researchers, who are considering its potential ramifications. “These molecules play such a crucial role in biological systems that understanding their structure would significantly advance the field. For example, we could use it to lay the foundation for building supramolecular structures by designing the dynamic collective movements of proteins. This concept can lead to the engineering of biocompatible sheet materials, targeted drug transports and even protein-based nanorobots, ”comments Professor Ueno.

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Materials provided by Tokyo Institute of Technology. Note: Content can be changed for style and length.