Domain Swapping Proceeds via Complete Unfolding: A 19F- and 1H-NMR Study of the Cyanovirin-N Protein
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- 作者：Lin Liu ; In-Ja L. Byeon ; Ivet Bahar ; Angela M. Gronenborn
- 刊名：The Journal of the American Chemical Society
- 出版年：2012
- 出版时间：March 7, 2012
- 年：2012
- 卷：134
- 期：9
- 页码：4229-4235
- 全文大小：349K
- 年卷期：v.134,no.9(March 7, 2012)
- ISSN：1520-5126
文摘
Domain swapping creates protein oligomers by exchange of structural units between identical monomers. At present, no unifying molecular mechanism of domain swapping has emerged. Here we used the protein Cyanovirin-N (CV鈥揘) and 19F-NMR to investigate the process of domain swapping. CV鈥揘 is an HIV inactivating protein that can exist as a monomer or a domain-swapped dimer. We measured thermodynamic and kinetic parameters of the conversion process and determined the size of the energy barrier between the two species. The barrier is very large and of similar magnitude to that for equilibrium unfolding of the protein. Therefore, for CV鈥揘, overall unfolding of the polypeptide is required for domain swapping.