Protein unfolding under isometric tension-what force can integrins generate, and can it unfold FNIII domains?

Journal Article (Journal Article;Review)

Extracellular matrix fibrils of fibronectin (FN) are highly elastic, and are typically stretched three to four times their relaxed length. The mechanism of stretching has been controversial, in particular whether it involves tension-induced unfolding of FNIII domains. Recent studies have found that ∼5pN is the threshold isometric force for unfolding various protein domains. FNIII domains should therefore not be unfolded until the tension approaches 5pN. Integrins have been reported to generate forces ranging from 1 to >50pN, but I argue that studies reporting 1-2pN are the most convincing. This is not enough to unfold FNIII domains. Even if domains were unfolded, 2pN would only extend the worm-like-chain to about twice the length of the folded domain. Overall I conclude that stretching FN matrix fibrils involves primarily the compact to extended conformational change of FN dimers, with minimal contribution from unfolding FNIII domains.

Full Text

Duke Authors

Cited Authors

  • Erickson, HP

Published Date

  • February 2017

Published In

Volume / Issue

  • 42 /

Start / End Page

  • 98 - 105

PubMed ID

  • 28038331

Pubmed Central ID

  • PMC5374013

Electronic International Standard Serial Number (EISSN)

  • 1879-033X

Digital Object Identifier (DOI)

  • 10.1016/


  • eng

Conference Location

  • England