M. Carvlin, N. Datta-gupta, R. Fiel
Sep 16, 1982
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0
Influential Citations
112
Citations
Quality indicators
Journal
Biochemical and biophysical research communications
Abstract
Recently, the porphyrin photosensitizer meso-tetra(4-N-methyl-pyridyl)-porphine was identified as a DNA-reactive agent demonstrating both electrostatic and intercalative binding. A series of porphyrin derivatives were synthesized and studied to see if similar compounds manifested identical behavior. One derivative, meso-tetra(p-N-trimethylanilinium) porphine did not exhibit intercalation behavior but did show avid binding and novel circular dichroic features when bound to B-form DNA. At an ionic strength of 1.02, the binding constant was found to be on the order of 104 and higher at lower ionic strength. The large binding constants and induced optical activity suggest that at large porphyrin/DNA ratios the final porphyrin · DNA complex may take the form of a suprahelical helix.