Spectroscopic study on the interaction of ct-DNA with manganese Salen complex containing triphenyl phosphonium groups.
The DNA binding properties of a bulky and hydrophobic Schiff base complex of manganese(III) [N,N'-bis(5-(triphenyl phosphonium methyl)salicylidene)-1,2-ethylene diamine chloride Mn(III) acetate] was examined by spectroscopic techniques. UV-vis titration data indicate both hypo and hyperchromic effect with addition of DNA to complex. A competitive binding study showed that the enhanced emission intensity of ethidium bromide (EB) in the presence of DNA was quenched by adding Mn Salen complex. This finding indicates that Mn Salen complex displaces EB from its binding site in DNA. Helix melting studies indicate improvement in the helix stability, and an increase in the melting temperature. The analysis of CD spectra represents the structural changes in DNA due to the binding of Mn Salen complex. The binding constant has been calculated using absorbance and fluorescence data. The results also represent that the binding process proceeds by strong electrostatic and hydrophobic interactions.
Department of Chemistry, University of Isfahan, Isfahan, Iran. nejatmari@yahoo.com
Maryam Nejat
MN
Dehkordi
Abdol-Khalegh
AK
Bordbar
Per
P
Lincoln
Valiollah
V
Mirkhani
D001665:Binding Sites; D001667:Binding, Competitive; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000378:metabolism*; D004996:Ethidium / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry* / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000737:chemistry* / Q000378:metabolism; D012545:Schiff Bases / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
C542902:Mn-salen; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; D012545:Schiff Bases; D004247:DNA; C427203:calf thymus DNA; D004996:Ethidium