title: Wide scale range structure in polyelectrolyte-protein dense complexes: where Sans meets freeze-fracture microscopy.
abstract: We show in this paper how the combination of SANS and freeze-fracture electron microscopy (FFEM) is a powerful tool to picture the structure of very turbid sample liquids at spatial scales lying from a few A to several microns. In a given range of chain size and species concentrations, primary complexes in the shape of globules are observed by both techniques. SANS allows a precise quantitation of size, inner structure, and composition of these globules, as well as aggregated structure of the globules at larger scales, which is fractal-like, with a Hausdorff dimension 2.1 characteristic of Reaction Limited Aggregation (RCLA). The existence of aggregates is seen by FFEM, but most of all FFEM shows the lack of any further structure at larger scale, up to the micrometer size.
authors.affiliation: Laboratoire Léon Brillouin, CEA Saclay, 91191 Gif sur Yvette, Cedex, France.
authors.forename: Jérémie
authors.initials: J
authors.lastname: Gummel
authors.forename: Fabrice
authors.initials: F
authors.lastname: Cousin
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Verbavatz
authors.forename: François
authors.initials: F
authors.lastname: Boué
mesh_terms: D000818:Animals; D004573:Electrolytes / Q000737:chemistry; D005614:Freeze Fracturing; D006801:Humans; D008854:Microscopy, Electron / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*
chemical_list: D004573:Electrolytes; D011108:Polymers; D011506:Proteins