WAVELENGTH DEPENDENCE FOR AMT CROSSLINKING OF pBR322 DNA

Gasparro, Francis P.; Saffran, Wilma A.; Cantor, Charles R.; Edelson, Richard L.

doi:10.1111/j.1751-1097.1984.tb04578.x

Cited by 29 publications

(14 citation statements)

References 18 publications

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“…NIR irradiation of psoTFOs with target DNA results exclusively in monoadducts. No interstrand crosslinks formed, consistent with previous observations that psoralens preferentially form monoadducts when excited at the red edge of their absorption spectrum (33)(34)(35)(36). These results indicate that NIR TPE and single-photon UVA irradiation, although formally possessing different selection rules for electronic transitions, excite HMT to electronic states that evolve to similar if not identical photochemically reactive states.…”

Section: Two-photon Excitation Generates Photoadducts In Cellssupporting

confidence: 79%

Spatially localized generation of nucleotide sequence-specific DNA damage

King²,

Boxer³

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

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Psoralens linked to triplex-forming oligonucleotides (psoTFOs) have been used in conjunction with laser-induced two-photon excitation (TPE) to damage a specific DNA target sequence. To demonstrate that TPE can initiate photochemistry resulting in psoralen-DNA photoadducts, target DNA sequences were incubated with psoTFOs to form triple-helical complexes and then irradiated in liquid solution with pulsed 765-nm laser light, which is half the quantum energy required for conventional one-photon excitation, as used in psoralen ؉ UV A radiation (320 -400 nm) therapy. Target DNA acquired strand-specific psoralen monoadducts in a light dose-dependent fashion. To localize DNA damage in a model tissue-like medium, a DNA-psoTFO mixture was prepared in a polyacrylamide gel and then irradiated with a converging laser beam targeting the rear of the gel. The highest number of photoadducts formed at the rear while relatively sparing DNA at the front of the gel, demonstrating spatial localization of sequence-specific DNA damage by TPE. To assess whether TPE treatment could be extended to cells without significant toxicity, cultured monolayers of normal human dermal fibroblasts were incubated with tritium-labeled psoralen without TFO to maximize detectable damage and irradiated by TPE. DNA from irradiated cells treated with psoralen exhibited a 4-to 7-fold increase in tritium activity relative to untreated controls. Functional survival assays indicated that the psoralen-TPE treatment was not toxic to cells. These results demonstrate that DNA damage can be simultaneously manipulated at the nucleotide level and in three dimensions. This approach for targeting photochemical DNA damage may have photochemotherapeutic applications in skin and other optically accessible tissues.

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Section: Two-photon Excitation Generates Photoadducts In Cellssupporting

confidence: 79%

Spatially localized generation of nucleotide sequence-specific DNA damage

King²,

Boxer³

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

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“…Cross-linked strands should rapidly reanneal upon neutralization (Gasparo et al, 1984). When both alkali and CaMV virions were present prior to dialysis of labelled BglII fragments, the radioactive DNA migrated as complexes of limited electrophoretic mobility (Fig.…”

Section: Demonstration Of Complex Formationmentioning

confidence: 99%

“…To cross-link (Gasparo et al, 1984) BgllI (BRL) fragments ofpCa37 (Y end-labelled or unlabelled), we irradiated 0.25 lag of DNA in the presence of 1-94 lag/ml 4,5",8-trimethylpsoralen (TMP; Aldrich) on a transilluminator (Fotodyne) for 60s. To determine whether cross-linking occurred under these conditions, we denatured TMP-treated and control samples for 10 rain at room temperature by addition of an excess of alkaline solution and separated the DNA molecules by electrophoresis in a gel of 1% agarose in TAE buffer as described above.…”

Section: S R Thompson and U Melchermentioning

confidence: 99%

Coat protein of cauliflower mosaic virus binds to ssDNA

Thompson

Melcher

1993

Journal of General Virology

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“…It has been well established that the furan-sice monoadduct can be easily driven to a diadduct in a double-stranded nucleic acid. Gasparro et al (1984) have reported the action spectrum for the AMT (4'-aminomethyl-4, 5', 8-trimethylpsoralen) crosslinking of pBR322 DMA in the wavelength region from 300 nm to 380 nm. They found that the wavelength dependence for crosslink formation correlates vizr.…”

Section: Introductionmentioning

confidence: 99%

“…Relatively little is known about the wavelength dependency of these photoreactions. Gasparro et al, 1984, have reported the action spectrum for the crosslinking of pBR322 DNA. They observed …”

Section: Introductionmentioning

confidence: 99%

Photochemistry of psoralen-DNA adducts, biological effects of psoralen-DNA adducts, applications of psoralen-DNA photochemistry

Shi¹

1988

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This thesis czr.sists of three main parts and totally eight ohacters. Ir. part I, I will present studies en the photochemistry ::psoraler.-DIIA adducts, specifically, the wavelength dependencies f:r the phot:reversals cf thyraidine-riMT (4' -hydrcxymethyi-4, :', 3-trir.er.thyipsoraien) mcr.cadducts and diadduct and the sarr.e adoucts incorporated in DMA helloes and the wavelength decer.decies for the ph:-ccorcsslir.kir.g cf thymidine-HMT mcr.cadducts in dcuhie-stranded helloes.In part II, I will report seme biological effects of psoralen-:;:".-, aiduccs, i.e., the effects on double-stranded DMA stability, DNA struoture, and transcription by E. coli and T7 RNA polymerases. Finally, Iwill focus on the applications of psoralen-DMA photochemistry to inves tigation cf protein-DIiA interaction during transcription, which includes the interaction cf E. coli and T7 RNA polymerases with D:;A in elongation complexes arrested at specific pscraien-DHA acduct sites as revealed by DMase I foctprinting experiments. DEDICATIONThis work is dedicated to Theresa Ng.

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WAVELENGTH DEPENDENCE FOR AMT CROSSLINKING OF pBR322 DNA

Cited by 29 publications

References 18 publications

Spatially localized generation of nucleotide sequence-specific DNA damage

Spatially localized generation of nucleotide sequence-specific DNA damage

Coat protein of cauliflower mosaic virus binds to ssDNA

Photochemistry of psoralen-DNA adducts, biological effects of psoralen-DNA adducts, applications of psoralen-DNA photochemistry

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