Investigation of Thionin–DNA Interaction by Satellite Hole Spectroscopy

Toxic interaction of thionine to deoxyribonucleic acids: Elucidation of the sequence specificity of binding with polynucleotides

“…The mode of DNA binding of thionine was speculated previously to be intercalative [14,27,41]. We confirmed the intercalative binding through viscometric and fluorescence quenching studies with natural DNAs [28].…”

“…They also proposed that a guaninecytosine (GC) specificity of thionine binding was not very marked. Using satellite hole spectroscopy, Chang et al [27] proposed a GC specific binding for thionine. Very recently, from a variety of biophysical and calorimetric studies with three natural DNAs of varying base compositions, we confirmed the intercalative binding and high affinity of thionine to GC rich DNAs [28].…”

Biophysical studies on the base specificity and energetics of the DNA interaction of photoactive dye thionine: Spectroscopic and calorimetric approach

“…The mode of DNA binding of thionine was speculated previously to be intercalative [15][16][17][18] and we probed the same using fluorescence quenching experiments in presence of [Fe(CN) 6 ] 4− . Quenching experiments are straight forward and indicate the location of the bound molecules to be either on the outside or inside of the helix.…”

“…Their studies also suggested that the guanine-cytosine (GC) specificity of thionine binding was not very marked. On the contrary, Chang et al [16] suggested a GC specific binding from satellite hole spectroscopy study. It was further suggested [17,18] that thionine exists in two different tautomeric forms and the amino form is intercalated while Biophysical Chemistry 148 (2010) 93-103 the imino form is not.…”

Calorimetric and thermal analysis studies on the binding of phenothiazinium dye thionine with DNA polynucleotides

“…These studies advance a classical intercalation model for thionine-DNA complexation. Furthermore, an overall guaninecytosine base pair specificity and alternating guanine-cytosine base pair selectivity have been reported recently from satellite hole spectroscopy and biophysical experiments [13,14]. Thermodynamics of the interaction of thionine by highly sensitive calorimetric experiments has been limited to a single report recently from our laboratory with three natural DNAs of guanine-cytosine composition varying from 28% to 72% [12].…”