Collapse of a long axis: single-molecule Forster resonance energy transfer and serpin equilibrium unfolding.

ABSTRACT: The energy required for mechanical inhibition of target proteases is stored in the native structure of inhibitory serpins and accessed by serpin structural remodeling. The overall serpin fold is ellipsoidal with one long and two short axes. Most of the structural remodeling required for function occurs along the long axis, while expansion of the short axes is associated with misfolded, inactive forms. This suggests that ellipticity, as typified by the long axis, may be important for both function and folding. Placement of donor and acceptor fluorophores approximately along the long axis or one of the short axes allows single-pair Förster resonance energy transfer (spFRET) to report on both unfolding transitions and the time-averaged shape of different conformations. Equilibrium unfolding a

SUBMITTER: Liu L 

PROVIDER: S-EPMC4020580 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature