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Revealing Conformational Variants of Solution‐Phase Intrinsically Disordered Tau Protein at the Single‐Molecule Level
Author(s) -
Manger Lydia H.,
Foote Alexander K.,
Wood Sharla L.,
Holden Michael R.,
Heylman Kevin D.,
Margittai Martin,
Goldsmith Randall H.
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201708242
Subject(s) - anisotropy , chemistry , chemical physics , fluorescence anisotropy , molecule , globular protein , phase (matter) , crystallography , brownian motion , intrinsically disordered proteins , electrokinetic phenomena , fluorescence , physics , biochemistry , optics , organic chemistry , quantum mechanics , membrane
Intrinsically disordered proteins, such as tau protein, adopt a variety of conformations in solution, complicating solution‐phase structural studies. We employed an anti‐Brownian electrokinetic (ABEL) trap to prolong measurements of single tau proteins in solution. Once trapped, we recorded the fluorescence anisotropy to investigate the diversity of conformations sampled by the single molecules. A distribution of anisotropy values obtained from trapped tau protein is conspicuously bimodal while those obtained by trapping a globular protein or individual fluorophores are not. Time‐resolved fluorescence anisotropy measurements were used to provide an explanation of the bimodal distribution as originating from a shift in the compaction of the two different families of conformations.