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Characterization of meningococcal polysaccharides by light‐scattering spectroscopy. IV. Molecular weight distribution of group B meningococcal polysaccharide in buffer solution
Author(s) -
Gulari Esin,
Chu B.,
Liu T. Y.
Publication year - 1979
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1979.360181204
Subject(s) - chemistry , radius of gyration , virial coefficient , analytical chemistry (journal) , molar mass distribution , radial distribution function , hydrodynamic radius , spectroscopy , polysaccharide , cyclohexane , crystallography , chromatography , aqueous solution , micelle , molecular dynamics , polymer , computational chemistry , organic chemistry , thermodynamics , physics , quantum mechanics
We report the first characterization of group B meningococcal polysaccharide at 28°C in 0.4 M KCl and 0.05 M sodium acetate at pH 5.61 and in pure water by means of light‐scattering spectroscopy. In buffer solution, the weight‐average molecular weight M r = 1.46 × 10 5 g/mol, the Z ‐average radius of gyration 〈 r g 2 〉 z 1/2 = 26.3 nm, the second virial coefficient A 2 = (2.12 ± 0.17) × 10 −4 cm 3 mol/g 2 , and the second virial coefficient of the diffusion expansion k D ≈ 79 g/g. By using a histogram approximation on the correlation function profile analysis, we observed size fractions of two sizes with r hL / r hS = 298 Å/50 Å and A L / A S = 82/18, where r h and A are the respective effective hydrodynamic radius and the integrated intensity and the subscripts L and S denote the large and small size fractions. In pure water, r hL / r hS = 402 Å/29 Å with A L / A S = 84/16. The linewidth results are consistent with the measurements on the angular distribution of scattered intensity. Furthermore, if we take the large fraction to behave more like solid spheres, we are able to determine a molecular weight distribution of B‐polysaccharide in buffer solution in a bimodal size distribution function.