Biochemistry (Moscow)

, Volume 71, Issue 3, pp 332–339

Determination of binding constants of lipopolysaccharides of different structure with chitosan

Authors

    • Pacific Institute of Bioorganic ChemistryFar-Eastern Division of the Russian Academy of Sciences
  • G. A. Naberezhnykh
    • Pacific Institute of Bioorganic ChemistryFar-Eastern Division of the Russian Academy of Sciences
  • I. M. Yermak
    • Pacific Institute of Bioorganic ChemistryFar-Eastern Division of the Russian Academy of Sciences
  • V. I. Gorbach
    • Pacific Institute of Bioorganic ChemistryFar-Eastern Division of the Russian Academy of Sciences
  • T. F. Solov’eva
    • Pacific Institute of Bioorganic ChemistryFar-Eastern Division of the Russian Academy of Sciences
Article

DOI: 10.1134/S0006297906030151

Cite this article as:
Davidova, V.N., Naberezhnykh, G.A., Yermak, I.M. et al. Biochemistry (Moscow) (2006) 71: 332. doi:10.1134/S0006297906030151

Abstract

The interaction of endotoxins—lipopolysaccharides (LPS) different in degree of the O-specific chain polymerization—with 20-and 130-kD chitosan was studied using the competitive binding of LPS with the complex of chitosananionic dye (tropaeolin 000-2) and the direct binding of 125I-labeled LPS with chitosan immobilized on Sepharose 4B. The interaction of 20-kD chitosan with LPS was non-cooperative, and immobilization of the polycation on Sepharose resulted in its binding to 125I-labeled LPS with a positive cooperativity. The interaction of LPS possessing a long O-specific chain with 130-kD chitosan was characterized by negative cooperativity. Binding constants of LPS with the polycation and the number of binding sites per amino group of chitosan were determined. The interaction affinity and stoichiometry of the LPS-chitosan complexes significantly depend on the LPS structure and concentration in the reaction mixture. The increase in the length of carbohydrate chains of LPS results in increase in the binding constants and decrease in the bound endotoxin amount.

Key words

lipopolysaccharidechitosantropaeolin 000-2binding constantsO-specific chain of LPS

Abbreviations

LPS

lipopolysaccharides

Ch-HM

high molecular weight chitosan (130 kD)

Ch-LM

low molecular weight chitosan (20 kD)

D0 and Dexp

absorption of solution before and after addition of LPS

ΔDmax

absorption difference of the tropaeolin-chitosan complex and tropaeolin-chitosan-LPS solution corresponding to chitosan saturation with LPS

Q

saturation degree of chitosan with LPS molecules

Kb

binding constant

Copyright information

© Pleiades Publishing, Inc. 2006