title: Proteins as micro viscosimeters: Brownian motion revisited.
abstract: 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.
authors.affiliation: Institut Curie-Recherche, Bâtiment 112, Centre Universitaire, 91405, Orsay, France. daniel.lavalette@curie.u-psud.fr
authors.forename: Daniel
authors.initials: D
authors.lastname: Lavalette
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hink
authors.forename: Martine
authors.initials: M
authors.lastname: Tourbez
authors.forename: Catherine
authors.initials: C
authors.lastname: Tétreau
authors.forename: Antonie J
authors.initials: AJ
authors.lastname: Visser
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D004058:Diffusion; D009038:Motion; D011506:Proteins / Q000737:chemistry*; D012399:Rotation; D013050:Spectrometry, Fluorescence; D014783:Viscosity
chemical_list: D011506:Proteins