Single-molecule spectroscopy reveals polymer effects of disordered proteins in crowded environments

• DOI: 10.1073/pnas.1322611111
• Publication Date: 2014-03-18T05:41:09Z
• Authors: Andrea Soranno; Iwo Koenig; Madeleine B. Borgia; Hagen Hofmann; Franziska Zosel; Daniel Nettels; Benjamin Schuler
• Keywords: 0301 basic medicine; 1000 Multidisciplinary; 0303 health sciences; Macromolecular Substances; Spectrum Analysis; Biophysics; Intrinsically Disordered Proteins; Molecular Weight; Solutions; 03 medical and health sciences; Biopolymers; 10019 Department of Biochemistry; Fluorescence Resonance Energy Transfer; 570 Life sciences; biology; Amino Acid Sequence; Hydrophobic and Hydrophilic Interactions; Protein Binding

SignificanceIn the interior of a cell, the volume accessible to each protein molecule is restricted by the presence of the large number of other macromolecules. Such a crowded environment is known to affect the stability and folding rates of proteins. In the case of intrinsically disordered proteins (IDPs), however, a class of proteins that lack stable structure, much less is known about the role of crowding effects. We have quantified the conformational changes occurring in IDPs in the presence of high concentrations of different polymers that act as crowding agents. Using single-molecule spectroscopy, we have identified effects that are typical of polymer solutions and have direct implications for the behavior of IDPs within the cell.