Proteins as micro viscosimeters: Brownian motion revisited.
Translational and rotational diffusion coefficients of proteins in solution strongly deviate from the Stokes-Einstein laws when the ambient viscosity is induced by macromolecular co-solutes rather than by a solvent of negligible size as was assumed by A. Einstein one century ago for deriving the laws of Brownian motion and diffusion. Rotational and translational motions experience different micro viscosities and both become a function of the size ratio of protein and macromolecular co-solute. Possible consequences upon fluorescence spectroscopy observations of diffusing proteins within living cells are discussed.
Lavalette
Daniel
D
Institut Curie-Recherche, Bâtiment 112, Centre Universitaire, 91405, Orsay, France. daniel.lavalette@curie.u-psud.fr
Hink
Mark A
MA
Tourbez
Martine
M
Tétreau
Catherine
C
Visser
Antonie J
AJ
D055592:Biophysical Phenomena; D001703:Biophysics; D004058:Diffusion; D009038:Motion; D011506:Proteins / Q000737:chemistry*; D012399:Rotation; D013050:Spectrometry, Fluorescence; D014783:Viscosity
D011506:Proteins