Probing the folded state of fibronectin type III domains in stretched fibrils by measuring buried cysteine accessibility.

Journal Article

Fibronectin (FN) is an extracellular matrix protein that is assembled into fibrils by cells during tissue morphogenesis and wound healing. FN matrix fibrils are highly elastic, but the mechanism of elasticity has been debated: it may be achieved by mechanical unfolding of FN-III domains or by a conformational change of the molecule without domain unfolding. Here, we investigate the folded state of FN-III domains in FN fibrils by measuring the accessibility of buried cysteines. Four of the 15 FN-III domains (III-2, -3, -9, and -11) appear to unfold in both stretched fibrils and in solution, suggesting that these domains spontaneously open and close even in the absence of tension. Two FN-III domains (III-6 and -12) appear to unfold only in fibrils and not in solution. These results suggest that domain unfolding can at best contribute partially to the 4-fold extensibility of fibronectin fibrils.

Full Text

Duke Authors

Cited Authors

  • Lemmon, CA; Ohashi, T; Erickson, HP

Published Date

  • July 29, 2011

Published In

Volume / Issue

  • 286 / 30

Start / End Page

  • 26375 - 26382

PubMed ID

  • 21652701

Electronic International Standard Serial Number (EISSN)

  • 1083-351X

Digital Object Identifier (DOI)

  • 10.1074/jbc.M111.240028

Language

  • eng

Conference Location

  • United States