Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
1992-7-21
pubmed:abstractText
Benzo[a]pyrene (BP) is an environmental genotoxin, which, following metabolic activation to 7,8-diol 9,10-epoxide (BPDE) derivatives, forms covalent adducts with cellular DNA. A major fraction of adducts are derived from the binding of N2 of guanine to the C10 position of BPDE. The mutagenic and carcinogenic potentials of these adducts are strongly dependent on the chirality at the four asymmetric benzylic carbon atoms. We report below on the combined NMR-energy minimization refinement characterization of the solution conformation of (-)-trans-anti-[BP]G positioned opposite C and flanked by G.C base pairs in the d(C1-C2-A3-T4-C5-[BP]G6-C7-T8-A9-C10-C11).d(G12-G13-T14++ +-A15-G16-C17- G18-A19-T20-G21-G22) duplex. Two-dimensional NMR techniques were applied to assign the exchangeable and non-exchangeable protons of the benzo[a]pyrenyl moiety and the nucleic acid in the modified duplex. These results establish Watson-Crick base pair alignment at the [BP]G6.C17 modification site, as well as the flanking C5.G18 and C7.G16 pairs within a regular right-handed helix. The solution structure of the (-)-trans-anti-[BP]G.C 11-mer duplex has been determined by incorporating intramolecular and intermolecular proton-proton distances defined by lower and upper bounds deduced from NOE buildup curves as constraints in energy minimization computations. The BP ring spans both strands of the duplex in the minor groove and is directed toward the 3'-end of the modified strand in the refined structure. One face of the BP ring of [BP]G6 stacks over the C17 residue across from it on the partner strand while the other face is exposed to solvent.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5245-52
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Influence of benzo[a]pyrene diol epoxide chirality on solution conformations of DNA covalent adducts: the (-)-trans-anti-[BP]G.C adduct structure and comparison with the (+)-trans-anti-[BP]G.C enantiomer.
pubmed:affiliation
Department of Biochemistry and Molecular Biophysics, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't