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SPECTROSCOPIC STUDI...
SPECTROSCOPIC STUDIES OF THE TRANS ADDUCTS DERIVED FROM (+)-ANTI-BENZO A PYRENE-7,8-DIHYDRODIOL-9,10-EPOXIDE AND (-)-ANTI-BENZO A PYRENE-7,8-DIHYDRODIOL-9,10-EPOXIDE AND THE OLIGONUCLEOTIDE 5'-D(CCTATAGATATCC)
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Ponten, I. (författare)
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- Kim, Seog K. (författare)
- Chalmers tekniska högskola,Chalmers University of Technology
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Graslund, A. (författare)
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- Nordén, Bengt, 1945 (författare)
- Chalmers tekniska högskola,Chalmers University of Technology
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Jernstrom, B. (författare)
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(creator_code:org_t)
- Oxford University Press (OUP), 1994
- 1994
- Engelska.
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Ingår i: Carcinogenesis. - : Oxford University Press (OUP). - 0143-3334 .- 1460-2180. ; 15:10, s. 2207-2213
- Relaterad länk:
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https://research.cha...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- The oligonucleotide 5'-d(CCTATAGATATCC) has been reacted with the (+)- or (-)-enantiomers of trans-7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene [(+)-and (-)-anti-BPDE respectively]. Consistent with previous studies employing single-stranded oligonucleotides, adduct formation of both anti-BPDE enantiomers preferentially involved trans-addition of the C10 position of the diol-epoxide to the exocyclic nitrogen of deoxyguanosine [in the following abbreviated as (+)-BPDE(t)-N-2-G and (-)-BPDE(t)-N-2-G adducts respectively]. The unmodified or (+)-BPDE(t)-N-2-G-modified oligonucleotide was allowed to form duplexes with the complementary sequence 5'-d(GGATATCTATAGG) or sequences in which C has been replaced with T, G or A and analysed with regard to thermal stability. The presence of a (+)-BPDE(t)-N-2-G adduct in oligonucleotide duplexes substantially decreased the value of the melting point relative to the corresponding unmodified duplex. In mismatched complexes containing the (+)-BPDE(t)-N-2-G adduct, a further decrease in thermal stability was observed. The presence of a (+)-BPDE(t)-N-2-G adduct did not seem to change the extent of hyperchromicity (approximate to 20%) upon melting. 5'-d(GGATATCTATAGG) or strands in which C was replaced with T,G or A were gradually added to (+)- or (-)-BPDE(t)-N-2-G-modified oligonucleotides and the fluorescence emission intensity was determined. In all cases with (+)-BPDE(t)-N-2-G, except when C was replaced with A in the complement, the fluorescence intensity steadily decreased and became constant at equal strand concentrations. When a strand containing A in place of C was gradually added to the (+)-BPDE(t)-N-2-G oligonucleotide, a marked increase in the fluorescence intensity was observed (>3-fold). In contrast, addition of strands containing A, T or G to the (-)-BPDE(t)-N-2-G-modified oligonucleotide increased tbe fluorescence intensity from 1.5- to >5-fold. Addition of the fully complementary sequence to the (-)-BPDE(t)-N-2-G-containing oligonucleotide resulted in reduced fluorescence, however less pronounced than with the (+)-BPDE(t)-N-2-G-modified analogue. Significant changes in spectral properties of the adducts were observed in the duplexes. The absorption and fluorescence excitation maxima of the single-stranded (+)-BPDE(t)-N-2-G-modified oligonucleotide were at 353 nm. Insertion of C or A opposite the adduct caused a significant shift of these maxima to shorter wavelengths (347-348 nm). Addition of acrylamide, a fluorescence quencher, reduced the fluorescence intensity in all cases, but to variable extents. The adducts not quenchable by acrylamide demonstrate spectral properties similar to those of the single-stranded (+)-BPDE(t)-N-2-G-modified oligonucleotide.
Ämnesord
- MEDICIN OCH HÄLSOVETENSKAP -- Klinisk medicin -- Cancer och onkologi (hsv//swe)
- MEDICAL AND HEALTH SCIENCES -- Clinical Medicine -- Cancer and Oncology (hsv//eng)
Nyckelord
- dihydrodiol epoxide
- specificity
- major adduct
- mutations
- benzo<a>pyrene diol epoxide
- dna-adducts
- solution conformation
- mutagenesis
- activation
- cells
Publikations- och innehållstyp
- art (ämneskategori)
- ref (ämneskategori)
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