title: Potential artifacts in using a glutathione S-transferase fusion protein system and spin labeling electron paramagnetic resonance methods to study protein-protein interactions.
abstract: Site-directed spin labeling electron paramagnetic resonance methods have been an important tool in studying protein-protein interactions. Labels are often attached to a cysteine residue, and spectra are acquired with and without binding partner(s) to provide information on the binding. This requires a knowledge of the label location which is simplified if the label remains faithfully attached to the designated residue in the complex. We report a system where this is not the case because the label was extracted by dialysis-resistant glutathione molecules. Once this artifact is identified, spectral subtraction provides a solution for meaningful data interpretation.
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, MC 111, Chicago, IL 60607, USA.
authors.forename: Chloe
authors.initials: C
authors.lastname: Antoniou
authors.forename: L W-M
authors.initials: LW
authors.lastname: Fung
mesh_terms: D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase