Study of poly(dA) structure in the acidic media

A. P. ANTONYAN; M. V. MINASYANTS; P. O. VARDEVANYAN

A. P. ANTONYAN Yerevan State University, Department of Biophysics
M. V. MINASYANTS Yerevan State University, Department of Biophysics
P. O. VARDEVANYAN Yerevan State University, Department of Biophysics

Keywords: Poly(dA) – ethidium bromide –absorption spectrum –intercalation –semi-intercalation – electrostatic binding

Abstract

The study of EtBr (ethidium bromide) interaction with poly(dA) at different pH of solution has been carried out. The obtained data revealed that poly(dA) depending on pH may be in different structural states – double-stranded at 4.0 > pH > 3.0 and singlestranded in neutral (pH≈7.0), weak acidic (6.0 > pH ≥ 5.5) and strong acidic (pH < 3.0) conditions. It was shown that EtBr binds to poly(dA) by intercalation at pH≈3.5 as well as semi-intercalation at pH≈7.0 and pH≈5.5 modes. From the obtained data it was also revealed that EtBr binding mechanisms are universal and practically do not depend on medium conditions.

Author Biographies

A. P. ANTONYAN, Yerevan State University, Department of Biophysics

Ա. Պ. Անտոնյան

M. V. MINASYANTS, Yerevan State University, Department of Biophysics

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P. O. VARDEVANYAN, Yerevan State University, Department of Biophysics

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