Tight binding of a copper (II) phthalocyanine (cuprolinic blue) to DNA.
The binding of a cationic phthalocyanine (Cuprolinic Blue) to calf thymus DNA, indicated by the increase in the DNA melting temperature and spectroscopic titration (Kaff greater than 10(7)M-1), was characterised by at least two distinct DNA-bound ligand forms possibly arising from intercalated and externally bound species each with Kaff values in the region 10(7) M-1. Evidence of strong intercalation was provided by gel electrophoresis of plasmid DNA in the presence of Cuprolinic Blue. The anionic phthalocyanine (copper phthalocyanine 3,4',4", 4"'-tetrasulfonic acid) does not bind to DNA by spectral criteria, reflecting electrostatic contributions to binding.
John
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DC
Department of Pharmacy, University of Manchester, U.K.
Rosamund
J
J
Douglas
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D004396:Coloring Agents; D004247:DNA; D007211:Indoles; D007700:Kinetics; D015394:Molecular Structure; D009942:Organometallic Compounds; D010860:Pigments, Biological; D010957:Plasmids
D004396:Coloring Agents; D007211:Indoles; D009942:Organometallic Compounds; D010860:Pigments, Biological; C015445:copper phthalocyanine; D004247:DNA