Ultrafast biomimetic oxidative folding of cysteine-rich peptides and microproteins in organic solvents

• Main Authors: Kam, Antony, Loo, Shining, Qiu, Yibo, Liu, Chuan-Fa, Tam, James P.
• Other Authors: School of Biological Sciences
• Format: Article
• Language: English
• Published: 2024
• Subjects: Medicine, Health and Life Sciences; Oxidative folding; Cysteine-rich peptides
• Online Access: https://hdl.handle.net/10356/175867
• Institution: Nanyang Technological University

Disulfides in peptides and proteins are essential for maintaining a properly folded structure. Their oxidative folding is invariably performed in an aqueous-buffered solution. However, this process is often slow and can lead to misfolded products. Here, we report a novel concept and strategy that is bio-inspired to mimic protein disulfide isomerase (PDI) by accelerating disulfide exchange rates many thousand-fold. The proposed strategy termed organic oxidative folding is performed under organic solvents to yield correctly folded cysteine-rich microproteins instantaneously without observable misfolded or dead-end products. Compared to conventional aqueous oxidative folding strategies, enormously large rate accelerations up to 113,200-fold were observed. The feasibility and generality of the organic oxidative folding strategy was successfully demonstrated on 15 cysteine-rich microproteins of different hydrophobicity, lengths (14 to 58 residues), and numbers of disulfides (2 to 5 disulfides), producing the native products in a second and in high yield.