Spectrin repeats are triple-helical coiled-coil domains found in many proteins that are regularly subjected to mechanical stress. We used atomic force microscopy technique and steered molecular dynamics simulations to study the behavior of a wild-type spectrin repeat and two mutants. The experiments indicate that spectrin repeats can form stable unfolding intermediates when subjected to external forces. In the simulations the unfolding proceeded via a variety of pathways. Stable intermediates were associated to kinking of the central helix close to a proline residue. A mutant stabilizing the central helix showed no intermediates in experiments, in agreement with simulation. Spectrin repeats may thus function as elastic elements, extendable to intermediate states at various lengths.
|Translated title of the contribution||Pathways and intermediates in forced unfolding of spectrin repeats|
|Pages (from-to)||1085 - 1096|
|Number of pages||12|
|Publication status||Published - Aug 2002|