Equilibrium binding of benzo(. alpha. )pyrene tetrol to synthetic polynucleotides: Sequence selectivity, thermodynamic properties, and ionic strength dependence

Journal Article · Tue Oct 04 00:00:00 EDT 1988 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00420a055· OSTI ID:6905872

Shimer, Jr, G H; Wolfe, A R; Meehan, T ^[1]

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1. Univ. of California, San Francisco (USA)

The authors have investigated the equilibrium binding of racemic 7r,8t,9t,10c-tetrahydroxy-7,8,9,10-tetrahydrobenzo({alpha})pyrene to the double-stranded, synthetic polynucleotides poly(d(A-T)), poly(d(G-C)), and poly(d(G-m{sup 5}C)) at low binding ratios. Difference absorption spectroscopy shows a 10-nm red shift for binding to poly(d(A-T)) and an 11-nm red shift for binding to either poly(d(G-C)) or poly(d(G-m{sup 5}C)). The value of {Delta}{epsilon} for binding is approximately the same for all three hydrocarbon-polynucleotide complexes. Binding of this neutral polycyclic aromatic hydrocarbon derivative to these polynucleotides is dependent upon ionic strength and temperature. Analysis of complex formation employing polyelectrolyte theory shows a greater release of counterions associated with binding to poly(d(A-T)) than with the other two polynucleotides (0.5 and ca. 0.36, respectively). Thus, sequence-selective binding of this hydrocarbon in DNA would be expected to change dependent on salt concentration. The temperature dependence of binding was studied at 100 mM Na{sup +} where the equilibrium binding constants for poly(d(A-T)) and poly(d(G-m{sup 5}C)) are roughly equivalent and 6-fold greater than the binding affinity for poly(d(G-C)).

• OSTI ID: 6905872
• Journal Information: Biochemistry; (USA), Vol. 27:20; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BENZOPYRENE
CROSS-LINKING
OLIGONUCLEOTIDES
ABSORPTION SPECTROSCOPY
BIOLOGICAL EFFECTS
DNA ADDUCTS
IONS
SODIUM COMPOUNDS
TEMPERATURE DEPENDENCE
ADDUCTS
ALKALI METAL COMPOUNDS
AROMATICS
CHARGED PARTICLES
CHEMICAL REACTIONS
CONDENSED AROMATICS
HYDROCARBONS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
POLYMERIZATION
SPECTROSCOPY
560300* - Chemicals Metabolism & Toxicology