Interaction of daunomycin antibiotic with histone H 1: ultraviolet spectroscopy and equilibrium dialysis studies

Abstract

Using ultraviolet spectroscopy and equilibrium dialysis techniques, we have investigated the interaction of anticancer drug, daunomycin with calf thymus histone H 1 chromosomal protein in 20 mM phosphate buffer, pH 7.0, 1 mM EDTA at room temperature. The UV spectroscopy results show that daunomycin (5.0–100 μM) decreases the absorbance of histone H 1 at 210–230 nm and induces hypochromicity in the absorption spectrum of the protein. The equilibrium dialysis data show that daunomycin binds to histone H 1 and the binding process is positive cooperative with two binding sites as Scatchard plot and Hill coefficient confirm it. The results suggest that daunomycin binds to histone H 1 and changes its conformation.