Ligand binding isotherm for DNA in the presence of supercoil-induced non-B form: a theoretical analysis.
A binding isotherm in the form of a modified McGhee-Von Hippel equation is proposed, on the basis of thermodynamical considerations, to include the non-cooperative binding of extended ligands to supercoiled DNA, where a stretch of non-B form may be present under superhelical stress. It is then studied, on the basis of a non-linear Scatchard plot, how the presence of an intercalating ligand can relax the supercoiled molecule and thus destabilise the non-B stretch, which may be recognised by the existence of a significant kink in the Scatchard plot.
Lahiri
A
A
Biophysics Division, Saha Institute of Nuclear Physics, 37 Belgachia Road, Calcutta 700037, India.
Majumdar
R
R