Chiral inversion mutagenesis identifies geometrically constrained residues within self-associating low-complexity
Ryan L Beckner1, Christien Carter1, Glen Liszczak1
1Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9038, USA.
Biorxiv : the Preprint Server for Biology
|December 25, 2025
Summary
Protein low-complexity domains (LCDs) self-associate for cellular functions. Chiral Inversion Mutagenesis (ChIM) reveals that Cα stereochemistry geometrically constrains LCD interactions, impacting protein self-association.
Area of Science:
- Biochemistry
- Structural Biology
- Molecular Biology
Background:
- Protein low-complexity domains (LCDs) are crucial for cellular functions through reversible self-association.
- The geometric constraints governing LCD-LCD interactions, beyond side-chain identity, are not fully understood.
- Globular protein folding is influenced by polypeptide homo-chirality, but its role in LCDs is unclear.
Purpose of the Study:
- To investigate the contribution of Cα stereochemistry to LCD self-association.
- To identify geometric constraints in LCD interactions using synthetic methods.
- To explore chemical strategies for probing LCD biochemistry.
Main Methods:
- Utilized protein total- and semi-synthesis.
- Employed synthetic Chiral Inversion Mutagenesis (ChIM) by introducing L-to-D amino acid inversions.
- Applied ChIM to the LCDs of Emerin and neurofilament light chain.
Main Results:
- Chiral inversion demonstrated position-dependent effects on LCD self-association.
- Identified specific Cα stereocenters under geometric constraint within LCDs.
- ChIM successfully probed LCD biochemistry without altering side-chain functionalities.
Conclusions:
- Cα stereochemistry is an essential structural feature influencing LCD self-association.
- Geometric constraints play a significant role in LCD-LCD interactions.
- ChIM provides a valuable chemical strategy for dissecting LCD structural biology.
Keywords:
Low-complexity domainschiral inversion mutagenesisprotein oligomerizationself-associationsynthetic protein chemistryMore Related Videos
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