Coiled-coil intermediate filament stutter instability and molecular unfolding

Melis Arslana, Zhao Qin, Markus J. Buehler

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Intermediate filaments (IFs) are the key components of cytoskeleton in eukaryotic cells and are critical for cell mechanics. The building block of IFs is a coiled-coil alpha-helical dimer, consisting of several domains that include linkers and other structural discontinuities. One of the discontinuities in the dimer's coiled-coil region is the so-called 'stutter' region. The stutter is a region where a variation of the amino acid sequence pattern from other parts of the alpha-helical domains of the protein is found. It was suggested in earlier works that due to this sequence variation, the perfect coiled-coil arrangement ceases to exist. Here, we show using explicit water molecular dynamics and well-tempered metadynamics that for the coil2 domain of vimentin IFs the stutter is more stable in a non-alpha-helical, unfolded state. This causes a local structural disturbance in the alpha helix, which has a global effect on the nanomechanics of the structure. Our analysis suggests that the stutter features an enhanced tendency to unfolding even under the absence of external forces, implying a much greater structural instability than previously assumed. As a result it features a smaller local bending stiffness than other segments and presents a seed for the initiation of molecular bending and unfolding at large deformation.

Original languageEnglish (US)
Pages (from-to)483-489
Number of pages7
JournalComputer Methods in Biomechanics and Biomedical Engineering
Volume14
Issue number5
DOIs
StatePublished - May 23 2011
Externally publishedYes

Keywords

  • Alpha helix
  • Coiled coil
  • Intermediate filaments
  • Materiomics
  • Nanomechanics
  • Protein

ASJC Scopus subject areas

  • Bioengineering
  • Biomedical Engineering
  • Human-Computer Interaction
  • Computer Science Applications

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