Conclusion
In summary, we have demonstrated how artificial molecular chaperones can serve opposite roles, i.e. catalyst or inhibitor, depending on their dosage in regulating the assembly of peptides. Low dosages of molecular chaperones catalyze peptide assembly into fibrils through multi-step phase separation, while high dosages trap peptides into coacervate intermediates and therefore inhibit assembly. This study provides a clue to elucidate the intricate relationship between phase separation and peptide assembly. When a phase separated system contains multiple components, additives, or impurities, careful examination of their dosage effects on assembly kinetics should not be overlooked. Moreover, this study provides insights into the multifaceted roles chaperones may play in regulating molecular assembly, facilitates the development of chaperone-assisted assembly strategy [24, 42, 43, 52-55] for the construction of complex assembly systems.
Materials and Methods
Detailed materials and methods are included in SI Appendix . The fibrillation of peptides was characterized by TEM, CLSM, ThT fluorescence, and CD. Interactions between CMD and peptides were studied by FRET, SPR, and ITC.
Acknowledgements
We thank Junjie Chen (Core Facility of Biomedical Sciences, Xiamen University, Xiamen 361001, PR China) for helpful discussion and assistance in the experiments. This work was supported by the National Natural Science Foundation of China (NSFC) (Nos. 21991130, 21991131, 21971216, 21971217, 22372139, 22250004), the Top-Notch Young Talents Program of China, and the Fundamental Research Funds for the Central Universities of China (No. 20720210007).
Conflict of Interests
The authors declare no competing interests.