Book of Abstracts: Albany 2011
June 14-18 2011
©Adenine Press (2010)
Dynamics of Two Combined Reversible Binding Ligands to DNA
Kinetic investigations on ligand binding to DNA describe the binding process as a function of time and allow getting information on rates of formation and dissociation of DNA-ligand complexes. Usually one works on binding kinetics of a single ligand binding on DNA. For examples of current study of ligand binding to nucleic acids, see references 1-5.
In this paper binding of two different ligands with DNA is considered under condtions in which both ligands occupy the same adsorption centers with different binding constants, and each ligand occupies different number of absoption centers. The ligand binding and dissociation of the complex can be represented as a discrete Markov process, and the derived differential equations describe the kinetics of combined binding of various ligands to DNA. Analysis of the data show that depending on adsorption parameters various modes of ligands binding to DNA may be realized.
Comparison of experimental curves of ligands interacting with DNA as a function of time with theoretical curves allows to determine the rate constants of formation and dissociation of DNA-ligand complex It is shown that the kinetics of DNA occupancy with a ligand of given type depends on the ratios between binding constant rates and concentration of ligands as well. Depending on their ratios, it may be possible that nonmonotonic change of number of ligands adsorbed on DNA over time may lead to inversion of ligand occupancy.
Valery B. Arakelyan1
1Department of Molecular Physics of Yerevan State University
A.Manooqian str. 1, Yerevan 0025, Armenia