Design of complicated all-α protein structures

Area of Science:

• Protein engineering
• Structural biology
• Computational chemistry

Background:

• De novo protein design has advanced significantly, yet struggles to replicate the complexity of natural protein structures.
• Existing methods often fall short in designing intricate, irregularly packed alpha-helical proteins.

Purpose of the Study:

• To develop a novel method for designing complex, 'difficult-to-describe' alpha-helical protein structures.
• To expand the diversity and complexity of de novo designed proteins, particularly those resembling globin structures.

Main Methods:

• Generated backbone structure libraries using combinations of helix-loop-helix motifs and canonical alpha-helices.
• Selected five distinct topologies for de novo design of five- or six-helix bundles.
• Utilized computational approaches to guide the design and predict structural outcomes.

Main Results:

• Successfully designed de novo alpha-helical proteins that are monomeric and exhibit high thermal stability.
• Experimental validation confirmed that the designed proteins fold into the intended topologies with atomic accuracy.
• Demonstrated the feasibility of creating complex alpha-helical protein structures from common structural motifs.

Conclusions:

• The developed method enables the design of intricate alpha-helical protein structures previously challenging to create.
• This approach utilizes typical protein building blocks to achieve high structural complexity.
• The findings open avenues for exploring a wider range of protein structures for novel functional protein design.