title: Surveying polypeptide and protein domain conformation and association with FlAsH and ReAsH.
abstract: Recombinant polypeptides and protein domains containing two cysteine pairs located distal in primary sequence but proximal in the native folded or assembled state are labeled selectively in vitro and in mammalian cells using the profluorescent biarsenical reagents FlAsH-EDT2 and ReAsH-EDT2. This strategy, termed bipartite tetracysteine display, enables the detection of protein-protein interactions and alternative protein conformations in live cells. As proof of principle, we show that the equilibrium stability and fluorescence intensity of polypeptide-biarsenical complexes correlates with the thermodynamic stability of the protein fold or assembly. Destabilized protein variants form less stable and less bright biarsenical complexes, which allows discrimination of live cells expressing folded polypeptide and protein domains from those containing disruptive point mutations. Bipartite tetracysteine display may provide a means to detect early protein misfolding events associated with Alzheimer's disease, Parkinson's disease and cystic fibrosis; it may also enable high-throughput screening of compounds that stabilize discrete protein folds.
authors.affiliation: Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, USA.
authors.forename: Nathan W
authors.initials: NW
authors.lastname: Luedtke
authors.forename: Rachel J
authors.initials: RJ
authors.lastname: Dexter
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Fried
authors.forename: Alanna
authors.initials: A
authors.lastname: Schepartz
mesh_terms: D000595:Amino Acid Sequence; D001152:Arsenicals / Q000737:chemistry*; D002470:Cell Survival; D002942:Circular Dichroism; D006367:HeLa Cells; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009930:Organic Chemicals / Q000737:chemistry; D010078:Oxazines / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011485:Protein Binding; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D001152:Arsenicals; D009930:Organic Chemicals; D010078:Oxazines; D010455:Peptides; D011506:Proteins; C454115:ReAsH-EDT2 compound; C071336:calcium green