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Rodlike complexes of a polyelectrolyte (hyaluronan) and a protein (lysozyme) observed by SANS

Authors :
Isabelle Grillo
François Boué
Fabrice Cousin
Eric Buhler
Isabelle Morfin
Laboratoire de Spectrométrie Physique (LSP)
Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)
Matière et Systèmes Complexes (MSC (UMR_7057))
Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Laboratoire Léon Brillouin (LLB - UMR 12)
Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay
Institut Laue-Langevin (ILL)
ILL
Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)
Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Matière et Systèmes Complexes (MSC)
Source :
Biomacromolecules, Biomacromolecules, American Chemical Society, 2011, 12, pp.859-870, Biomacromolecules, American Chemical Society, 2012, 12, pp.859-870. ⟨10.1021/bm100861g⟩, Biomacromolecules, 2012, 12, pp.859-870. ⟨10.1021/bm100861g⟩
Publication Year :
2011

Abstract

International audience; We study by Small Angle Neutron Scattering (SANS) the structure of Hyaluronan -Lysozyme complexes. Hyaluronan (HA) is a polysaccharide of 9 nm intrinsic persistence length that bears one negative charge per disaccharide monomer (Mmol = 401.3 g/mol); two molecular weights, Mw = 6000 and 500 000 Da were used. The pH was adjusted at 4.7 and 7.4 so that lysozyme has a global charge of +10 and + 8 respectively. The lysozyme concentration was varied from 3 to 40 g/L, at constant HA concentration (10 g/L). At low protein concentration, samples are monophasic and SANS experiments reveal only fluctuations of concentration although, at high protein concentration, clusters are observed by SANS in the dense phase of the diphasic samples. In between, close to the onset of the phase separation, a distinct original scattering is observed. It is characteristic of a rod-like shape, which could characterize "single" complexes involving one or a few polymer chains. For the large molecular weight (500 000) the rodlike rigid domains extend to much larger length scale than the persistence length of the HA chain alone in solution and the range of the SANS investigation. They can be described as a necklace of proteins attached along a backbone of diameter one or a few HA chains. For the short chains (Mw ~ 6000), the rod length of the complexes is close to the chain contour length (~ 15 nm).

Details

ISSN :
15264602 and 15257797
Volume :
12
Issue :
4
Database :
OpenAIRE
Journal :
Biomacromolecules
Accession number :
edsair.doi.dedup.....285927262003d6b20c6f3c8039f867e8