Anomalous small angle x-ray scattering determination of ion distribution around a polyelectrolyte biopolymer in salt solution.

The distribution of counterions in solutions of high molecular mass hyaluronic acid, in near-physiological conditions where mono- and divalent ions are simultaneously present, is studied by small angle neutron scattering and anomalous small angle x-ray scattering. The solutions contain either sodium or rubidium chloride together with varying concentrations of calcium or strontium chloride. The effects of monovalent-divalent ion exchange dominate the amplitude and the form of the counterion cloud. In the absence of divalent ions, the shape of the anomalous scattering signal from the monovalent ions is consistent with the distribution calculated from the Poisson-Boltzmann equation, as found by other workers. In mixtures of monovalent and divalent ions, however, as the divalent ion concentration increases, both the diameter and the amplitude of the monovalent ion cloud decrease. The divalent counterions always occupy the immediate neighborhood of the charged polyanion. Above a given concentration their anomalous scattering signal saturates. Even in a large excess of divalent ions, ion exchange is incomplete.

[1]  M. Ballauff,et al.  Correlations and fluctuations of charged colloids as determined by anomalous small-angle X-ray scattering , 2006 .

[2]  J. Israelachvili,et al.  Lubrication and wear properties of grafted polyelectrolytes, hyaluronan and hylan, measured in the surface forces apparatus. , 2004, Journal of biomedical materials research. Part A.

[3]  P. Basser,et al.  Adsorption of divalent cations on DNA. , 2004, Biophysical journal.

[4]  T. Narayanan,et al.  Analysis of the correlation of counterions to rod-like macroions by anomalous small-angle X-ray scattering , 2004 .

[5]  G. Goerigk,et al.  The distribution of Sr2+ counterions around polyacrylate chains analyzed by anomalous small-angle X-ray scattering , 2004 .

[6]  M. Muthukumar,et al.  Theory of counter-ion condensation on flexible polyelectrolytes: adsorption mechanism. , 2004, The Journal of chemical physics.

[7]  P. Basser,et al.  Ion condensation in a polyelectrolyte gel , 2003 .

[8]  T. Narayanan,et al.  Use of anomalous small-angle X-ray scattering for the investigation of highly charged colloids , 2003 .

[9]  Rhiju Das,et al.  Counterion distribution around DNA probed by solution X-ray scattering. , 2003, Physical review letters.

[10]  S. Harding,et al.  Hydrodynamic characterisation of chemically degraded hyaluronic acid , 2003 .

[11]  P. Basser,et al.  Experimental evidence for two thermodynamic length scales in neutralized polyacrylate gels , 2002 .

[12]  M. Ballauff,et al.  The distribution of counterions around synthetic rod-like polyelectrolytes in solution , 2002, The European physical journal. E, Soft matter.

[13]  A. Jamieson,et al.  Viscoelastic properties of aggrecan aggregate solutions: Dependence on aggrecan concentration and ionic strength , 2002 .

[14]  J. Douglas,et al.  Influence of counterion valency on the scattering properties of highly charged polyelectrolyte solutions , 2001 .

[15]  D. Bratko,et al.  Multivalent ion-DNA interaction: Neutron scattering estimates of polyamine distribution , 1999 .

[16]  P. Lesieur,et al.  Ionic distribution and polymer conformation, near phase separation, in sodium polyacrylate/divalent cations mixtures: small angle X-ray and neutron scattering , 1999 .

[17]  A. Yethiraj,et al.  Density Functional Theory for the Distribution of Small Ions around Polyions , 1999 .

[18]  M. Deserno,et al.  Fraction of Condensed Counterions around a Charged Rod: Comparison of Poisson−Boltzmann Theory and Computer Simulations , 1999, cond-mat/9906277.

[19]  M. Stevens.  Bundle Binding in Polyelectrolyte Solutions , 1999 .

[20]  M. Muthukumar.  DOUBLE SCREENING IN POLYELECTROLYTE SOLUTIONS : LIMITING LAWS AND CROSSOVER FORMULAS , 1996 .

[21]  M. Cowman,et al.  13C-NMR Studies of Hyaluronan: Conformational Sensitivity to Varied Environments† , 1996 .

[22]  Sow-Hsin Chen,et al.  Measurements of monovalent and divalent counterion distributions around persistence length DNA fragments in solution , 1990 .

[23]  S. Marčelja,et al.  Correlation and image charge effects in electric double layers , 1984 .

[24]  D. T. Cromer,et al.  Anomalous dispersion calculations near to and on the long-wavelength side of an absorption edge , 1981 .

[25]  R. Cleland.  The persistence length of hyaluronic acid: an estimate from small-angle x-ray scattering and intrinsic viscosity. , 1977, Archives of biochemistry and biophysics.

[26]  E. Radin,et al.  Separation of a Hyaluronate-free Lubricating Fraction from Synovial Fluid , 1970, Nature.

[27]  L. Rosenberg,et al.  Macromolecular models of proteinpolysaccharides from bovine nasal cartilage based on electron microscopic studies. , 1970, The Journal of biological chemistry.

[28]  G. S. Manning.  Limiting Laws and Counterion Condensation in Polyelectrolyte Solutions II. Self‐Diffusion of the Small Ions , 1969 .

[29]  A. Ogston,et al.  The physiological function of hyaluronic acid in synovial fluid; viscous, elastic and lubricant properties , 1953, The Journal of physiology.

[30]  Herbert Morawetz,et al.  The counterion distribution in solutions of rod‐shaped polyelectrolytes , 1951 .

[31]  A Katchalsky,et al.  The Potential of an Infinite Rod-Like Molecule and the Distribution of the Counter Ions. , 1951, Proceedings of the National Academy of Sciences of the United States of America.

[32]  M. Stevens.  Simple simulations of DNA condensation. , 2001, Biophysical journal.

[33]  P. Basser,et al.  Effect of monovalent-divalent cation exchange on the swelling of polyacrylate hydrogels in physiological salt solutions. , 2001, Biomacromolecules.

[34]  V. F. Sears.  Neutron scattering lengths and cross sections , 1992 .

[35]  W. Jesse,et al.  Partial and charge structure fonctions of monodisperse DNA fragments in salt free aqueous solution , 1992 .