Open AccessInfluence of pH and Metal Ions on the Fluorescence of Polycyclic Hydrocarbons in Aqueous DNA Solution
Author(s) -
Green Brian
Publication year - 1970
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1970.tb00325.x
Subject(s) - pyrene , chemistry , dna , perylene , aqueous solution , metal ions in aqueous solution , quenching (fluorescence) , metal , inorganic chemistry , ionic strength , fluorescence , polycyclic aromatic hydrocarbon , hydrocarbon , ion , carcinogen , ionic bonding , photochemistry , phosphate , nuclear chemistry , molecule , organic chemistry , biochemistry , physics , quantum mechanics
The fluorescence of benzo[α]pyrene or perylene solubilized in DNA solutions of low ionic strength is strongly quenched either by addition of silver ions at a ratio Ag + :DNA phosphate < 0.15 or by lowering the pH from 7.5 to 5. In poly d(A‐T) solutions the effects are much less marked than in DNA. Cu 2+ ions are also effective quenchers in this system and Co 2+ and Ni 2+ have some activity but little effect is seen with Mn 2+ , Zn 2+ , Cd 2− , Mg 2+ or Na + ions. The results establish that GC pairs play the dominant role in these quenching reactions and show that the DNA bases have a specific role in the DNA/hydrocarbon interaction. They also suggest that GC‐containing sites are the major sites of physicochemical fixation of hydrocarbons to DNA. No gross difference in the general nature of the DNA binding sites was found for the carcinogenic benzo[α]pyrene and non carcinogenic perylene.