PHYSICAL-CHEMICAL PROPERTIES OF CHONDROITIN SULFATE IN AGGRECAN
Abstract
In current work theoretical study of physical-chemical properties of chondroitin sulfate in aggrecan within the self-consistent field theory was developed. As a model for aggrecan a model of cylindrical polymer brush was chosen. Aggrecan is considered as a system of n gaussian polymer chains consisting of N segments tethered to cylindrical surface of core protein. Basing on the results of previous work where using gaussian equivalent representation for functional integrals equation of state for chondroitin sulfate in aqueous solution was obtained and also osmotic pressure, dissociation degree, radius of gyration and renormalized persistent length were calculated with respect to monomers electrostatic interactions and effect of counterion condensation, one can obtain configuration integral for cylindrical polymer brush. Persistent length is introduced instead of Kuhn segment length which supposedly helps one to take into account rigidity of polymer chain determined by electrostatic repulsion of monomers (disaccharides groups). Expression for free energy of a polymer brush modeled as chondroitin sulfate chains tethered to a cylindrical surface was obtained. Dependence of chondroitin sulfate in aggrecan dissociation degree as a function of distance from the cylindrical surface is represented. For given system it varies insignificantly from the one for free chains in solution. Results for a polymer density as a function of distance from the cylindrical surface obtained within mean-field approximation are in qualitative agreement with those obtained using density functional method. However, calculations within a mean field framework are understable, thus it is necessary to use regularization methods.
Forcitation:
NogovitsynE.A., KalikinN.N., ZheleznyakN.I. Physical-chemical properties of chondroitin sulfate in aggrecan. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018.
V. 61. N 2. P. 35-39
References
Vavilova T.P. Biochemistry of tissues and fluids of the oral cavity. М.: GEOTAR-MEDIA. 2008. 208 p. (in Russian).
Nap R. J., Szleifer I. Structure and interactions of aggrecans: statistical thermodynamic approach. Biophys. J. 2008. V. 95. P. 4570–4583. DOI: 10.1529/biophysj.108.133801.
Bathe M., Rutledge G.C., Grodzinsky A.J., Tidor B. A coarse-grained molecular model for glycosaminoglycans: application to chondroitin, chondroitin sulfate, and hyaluronic acid. Biophys. J. 2005. V. 88. P. 3870-3887. DOI: 10.1529/biophysj.104.058800.
Baeurle S.A., Kiselev M.G., Makarova E.S., Nogovitsin E.A. Effect of the counterion behavior on the frictional-compressive properties of chondroitin sulfate solutions. Polymer. 2009. V. 50. P. 1805-1813. DOI: 10.1016/j.polymer.2009.01.066.
Nogovitsyn E.A., Kolesnikov A.L., Budkov Yu.A. Field-theoretical model of electrolytic dissociation in polyelectrolyte solu-tions. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2013. V. 56. N 2. P. 36-39 (in Russian).
Kolesnikov A.L., Budkov Yu.A., Nogovitsyn E.A. Coarse-grained model of glycosaminoglycans in aqueous salt solutions. A field-theoretical approach. J. Phys. Chem. B. 2014. V. 118. P. 13037-13049. DOI: 10.1021/jp503749a.
Fredrickson G.H. The equilibrium theory of inhomogeneous polymers. Oxford: Clarendon Press. 2005. 407 p.
Netz R.R., Schick M. Classical theory of polymer brushes. Euro. Phys. Lett. 1997. V. 38. N 1. P. 37-42.
Binder K., Milchev A. Polymer brushes on flat and curved surfaces: How computer simulation can help to test theories and to interpret experiments. J. Polym. Sc. B. Polymer Phys. 2012. 50. P. 1515. DOI: 10.1002/polb.23168.
Alibekov I.Yu. Numerical Methods. Moscow: MSIU. 2008. 220 p. (in Russian).
