Cysteine-based protein folding modulators for trapping intermediates and misfolded forms

Area of Science:

• Biochemistry
• Molecular Biology
• Protein Chemistry

Background:

• Protein folding is crucial for biological function, with on-pathway intermediates yielding native structures and off-pathway intermediates leading to disease-associated non-native forms.
• Investigating folding intermediates and misfolded proteins is vital for understanding disease mechanisms.

Purpose of the Study:

• To develop novel cysteine-based molecular modulators for controlling protein folding pathways.
• To investigate the use of these modulators in trapping proteins in non-native conformations.

Main Methods:

• Synthesis of cysteine-containing dipeptides conjugated with amino acids bearing mono- and diamino-groups.
• Application of these dipeptides in oxidative protein folding experiments, monitoring disulfide-bond formation and protein conformations.

Main Results:

• Cysteine and oxidized glutathione promoted native protein folding.
• The developed dipeptides accelerated disulfide-bond formation but significantly increased the yield of non-native protein isomers.
• This indicates a molecular design for inducing non-native conformations through intermolecular disulfide bonds.

Conclusions:

• The study presents a molecular design for cysteine-based protein-folding modulators.
• These modulators facilitate the formation of non-native protein conformations via intermolecular disulfide bonds.
• The reversible nature of disulfide bonds suggests potential for reversible trapping and refolding strategies for transient and misfolded protein forms.