Evidences for the unfolding mechanism of three-dimensional domain swapping

Authors

  • Zhirong Liu,

    Corresponding author
    1. College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
    2. Beijing National Laboratory for Molecular Sciences (BNLMS), Peking University, Beijing 100871, China
    3. Center for Quantitative Biology, Peking University, Beijing 100871, China
    • College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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  • Yongqi Huang

    1. College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
    2. Beijing National Laboratory for Molecular Sciences (BNLMS), Peking University, Beijing 100871, China
    3. Center for Quantitative Biology, Peking University, Beijing 100871, China
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Abstract

The full or partial unfolding of proteins is widely believed to play an essential role in three-dimensional domain swapping. However, there is little research that has rigorously evaluated the association between domain swapping and protein folding/unfolding. Here, we examined a kinetic model in which domain swapping occurred via the denatured state produced by the complete unfolding of proteins. The relationships between swapping kinetics and folding/unfolding thermodynamics were established, which were further adopted as criteria to show that the proposed mechanism dominates in three representative proteins: Cyanovirin-N (CV-N), the C-terminal domain of SARS-CoV main protease (Mpro-C), and a single mutant of oxidized thioredoxin (Trx_W28Aox).

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