Binding of a porphyrin conjugate of Hoechst 33258 to DNA. I. UV-visible and melting studies detect multiple binding modes to a 12-mer nonself-complementary duplex.
Relative to ligand-free duplex DNA, the melting temperature of the 1:1 complex of the duplex d(CGAATTGTATGC):d(GCATACAATTCG) with the conjugate of Hoechst 33258 with a des-metalloporphyrin, increased from 42 to 60.5 degrees C indicating strong ligand binding. UV-vis spectrophotometric titration detected more than one class of binding site (apparent dissociation constants approximately 0.2 microM for simple noncooperative binding and 1 microM for the simultaneous cooperative mode with Hill coefficient approximately 2).
Frau
S
S
School of Pharmacy and Pharmaceutical Sciences, University of Manchester, UK.
Bichenkova
E V
EV
Fedorova
O S
OS
Lokhov
S
S
Douglas
K T
KT
D001665:Binding Sites; D006690:Bisbenzimidazole / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D018076:DNA, Complementary / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D009691:Nucleic Acid Denaturation; D009841:Oligonucleotides / Q000737:chemistry; D011166:Porphyrins / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D018076:DNA, Complementary; D005456:Fluorescent Dyes; D008024:Ligands; D009841:Oligonucleotides; D011166:Porphyrins; D004247:DNA; D006690:Bisbenzimidazole