SUNY at Albany
June 19-23, 2001
pH-Induced Helix-Coil Transition of EtBr Ð DNA Complexes
Helix-coil transition of DNA Ð Ethidium Bromide (EtBr) complexes has been investigated using variation of pH as a melting factor at low range of pH. It has been shown that EtBr stabilized the helix structure of DNA preferentially interacting with AT base pairs of the biopolimer. This resulted in decreased transition-width of the complexes
with respect to that of "pure" DNA
at low EtBr concentrations
(c=EtBr/DNA b.p. £0.02)
.Upon further increase in ligand concentration
increased and at
became equal to
.The point of transition
decreased monotonically at the all range of variation of c.
Ara P. Antonyan, Pogos O. Vardevanyan and Armen T. Karapetian(1)*.
Biophysics Department of Yerevan State University, Yerevan 375025, Armenia.