The folding pathway of a fast-folding immunoglobulin domain revealed by single-molecule mechanical experiments

Ingo Schwaiger, Michael Schleicher, Angelika A. Noegel, Matthias Rief

Research output: Contribution to journalArticlepeer-review

72 Scopus citations

Abstract

The F-actin crosslinker filamin from Dictyostelium discoideum (ddFLN) has a rod domain consisting of six structurally similar immunoglobulin domains. When subjected to a stretching force, domain 4 unfolds at a lower force than all the other domains in the chain. Moreover, this domain shows a stable intermediate along its mechanical unfolding pathway. We have developed a mechanical single-molecule analogue to a double-jump stopped-flow experiment to investigate the folding kinetics and pathway of this domain. We show that an obligatory and productive intermediate also occurs on the folding pathway of the domain. Identical mechanical properties suggest that the unfolding and refolding intermediates are closely related. The folding process can be divided into two consecutive steps: in the first step 60 C-terminal amino acids form an intermediate at the rate of 55s-1; and in the second step the remaining 40 amino acids are packed on this core at the rate of 179s -1. This division increases the overall folding rate of this domain by a factor of ten compared with all other homologous domains of ddFLN that lack the folding intermediate.

Original languageEnglish
Pages (from-to)46-51
Number of pages6
JournalEMBO Reports
Volume6
Issue number1
DOIs
StatePublished - 2005

Keywords

  • Atomic force microscope
  • Filamin
  • Folding kinetics

Fingerprint

Dive into the research topics of 'The folding pathway of a fast-folding immunoglobulin domain revealed by single-molecule mechanical experiments'. Together they form a unique fingerprint.

Cite this