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A Single-Molecule Strategy to Capture Non-native Intramolecular and Intermolecular Protein Disulfide Bridges.

Marc MoraStephanie BoardOlivier Languin-CattoënLaura MasinoGuillaume StirnemannSergi Garcia-Manyes
Published in: Nano letters (2022)
Non-native disulfide bonds are dynamic covalent bridges that form post-translationally between two cysteines within the same protein (intramolecular) or with a neighboring protein (intermolecular), frequently due to changes in the cellular redox potential. The reversible formation of non-native disulfides is intimately linked to alterations in protein function; while they can provide a mechanism to protect against cysteine overoxidation, they are also involved in the early stages of protein multimerization, a hallmark of several protein aggregation diseases. Yet their identification using current protein chemistry technology remains challenging, mainly because of their fleeting reactivity. Here, we use single-molecule spectroscopy AFM and molecular dynamics simulations to capture both intra- and intermolecular disulfide bonds in γD-crystallin, a cysteine-rich, structural human lens protein involved in age-related eye cataracts. Our approach showcases the power of mechanical force as a conformational probe in dynamically evolving proteins and presents a platform to detect non-native disulfide bridges with single-molecule resolution.
Keyphrases
  • single molecule
  • living cells
  • protein protein
  • molecular dynamics simulations
  • atomic force microscopy
  • amino acid
  • binding protein
  • endothelial cells
  • climate change
  • quantum dots
  • molecular dynamics
  • fluorescent probe