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Excluded‐Volume Effects in Living Cells
Author(s) -
Gnutt David,
Gao Mimi,
Brylski Oliver,
Heyden Matthias,
Ebbinghaus Simon
Publication year - 2015
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201409847
Subject(s) - macromolecular crowding , crowding , lysis , macromolecule , biophysics , förster resonance energy transfer , biomolecule , cell , nanotechnology , chemistry , excluded volume , polymer , materials science , biology , biochemistry , fluorescence , neuroscience , physics , organic chemistry , quantum mechanics
Biomolecules evolve and function in densely crowded and highly heterogeneous cellular environments. Such conditions are often mimicked in the test tube by the addition of artificial macromolecular crowding agents. Still, it is unclear if such cosolutes indeed reflect the physicochemical properties of the cellular environment as the in‐cell crowding effect has not yet been quantified. We have developed a macromolecular crowding sensor based on a FRET‐labeled polymer to probe the macromolecular crowding effect inside single living cells. Surprisingly, we find that excluded‐volume effects, although observed in the presence of artificial crowding agents, do not lead to a compression of the sensor in the cell. The average conformation of the sensor is similar to that in aqueous buffer solution and cell lysate. However, the in‐cell crowding effect is distributed heterogeneously and changes significantly upon cell stress. We present a tool to systematically study the in‐cell crowding effect as a modulator of biomolecular reactions.