Reaction of the 7,8-diol 9,10-epoxide of benzo(a)pyrene with guanine in DNA. Ab initio calculations and proposed reaction mechanism

Journal Article · Wed Mar 19 23:00:00 EST 1980 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100443a016· OSTI ID:5266644

Lin, J ^[1]; LeBreton, P R; Shipman, L L

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1. Univ. of Illinois, Chicago

The molecular fragment floating spherical Gaussian orbital method has been used to study model complexes related to the reaction between 7..beta..,8..cap alpha..-dihydroxy-7,8,9,10-tetrahydrobenzo(a)pyrene 9..cap alpha..,10..cap alpha..-oxide and guanine in DNA. The results of these calculations in combination with previous theoretical and experimental results suggest that the reaction proceeds via a three-step mechanism: (1) formation of a physical complex in which the pyrene moiety of the diol epoxide intercalates between base pairs of DNA and the reduced hydrophilic ring extends outside the helix into solution; (2) acid-catalyzed epoxide ring opening to form the 7,8,9-triol carbonium ion; and (3) formation of a C/sub 10/-N/sub 2/ covalent bond and deprotonation of N/sub 2/ to form the experimentally observed covalently linked product.

• OSTI ID: 5266644
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 84:6; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ALCOHOLS
AMINES
AROMATICS
BENZOPYRENE
BIOCHEMICAL REACTION KINETICS
CONDENSED AROMATICS
DATA
DATA FORMS
DNA
EPOXIDES
EXPERIMENTAL DATA
GLYCOLS
GUANINE
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
HYDROXY COMPOUNDS
INFORMATION
ISOLATED VALUES
KINETICS
NUCLEIC ACIDS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PURINES
REACTION KINETICS