Anisotropic deformation response of single protein molecules

Hendrik Dietz, Felix Berkemeier, Morten Bertz, Matthias Rief

Research output: Contribution to journalArticle

204 Citations (Scopus)

Abstract

Single-molecule methods have given experimental access to the mechanical properties of single protein molecules. So far, access has been limited to mostly one spatial direction of force application. Here, we report single-molecule experiments that explore the mechanical properties of a folded protein structure in precisely controlled directions by applying force to selected amino acid pairs. We investigated the deformation response of GFP in five selected directions. We found fracture forces widely varying from 100 pN up to 600 pN. We show that straining the GFP structure in one of the five directions induces partial fracture of the protein into a half-folded intermediate structure. From potential widths we estimated directional spring constants of the GFP structure and found values ranging from 1 N/m up to 17 N/m. Our results show that classical continuum mechanics and simple mechanistic models fail to describe the complex mechanics of the GFP protein structure and offer insights into the mechanical design of protein materials.

Original languageEnglish
Pages (from-to)12724-12728
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume103
Issue number34
DOIs
Publication statusPublished - 2006 Aug 22

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Keywords

  • Cysteine engineering
  • GFP
  • Protein mechanics
  • Protein stability
  • Single-molecule force spectroscopy

ASJC Scopus subject areas

  • General

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