Book of Abstracts: Albany 2003
June 17-21 2003
Disperse of Bound Ligands Method in Study of Adsorption Isotherm
By a method of absorption spectroscopy the binding of Ethidium Bromide, Mitokcantrone and Ametotrone with synthetic double-stranded polynucleotides poly (G)-poly(C), poly(I)-poly (C) as well as with calf thymus DNA is investigated. Isotherms of adsorption are analysed within the framework of Crousers-Gurskii's model. It is shown, that the parameters of adsorption (K - binding constant, n - binding site size) can be determined proceeding from the analysis of disperse of the bound molecules quantity (1). However, for above-mentioned complexes experimental determination of the physical characteristics of the completely bound condition of ligand with DNA is extremely difficult. It is possible to determine the only approached values of binding parameters from the standard representated adsorption isotherms in Scatchard`s coordinates. Therefore, in some cases the offered method can appear rather informative at an estimation of ligand binding parameters with DNA.
Taking into account data obtained by above-stated method, with the greater accuracy the constants of above-mentioned ligands with double-stranded polinucleotides are determined.
P. O. Vardevanyan1
1Biophysics Department of Yerevan State University