Abstract
Experiments with calf thymus DNA subjected to extracellular irradiation yield information on the role of direct and indirect effects in single-strand breakage, if this is evaluated with reference to the scavenger activity in respect of OH radicals. The role of the two processes in the occurrence of double-stand breaks and further damage leading to cell decay has so far remained largely obscure. It was the aim of the study described here to contribute to research in this field by performing in vitro experiments on biologically active DNA. For this purpose, DNA from pBR322 plasmids was irradiated in the presence of OH-radical scavengers. The number of single-strand and double-strand breaks was determined on the basis of the system`s ability to eliminate OH radicals. In order to asses the influence of irradiation processes on the biological activity of DNA, investigations were carried out in E. coli for transformations caused by irradiated plasmid DNA. The results were interpreted in the light of theories about inhomogenous reaction kinetics put forward by Mark et al. (1989). It was finally discussed, which of the gamma-irradiation injuries occurring in DNA was to be held responsible for the inactivation of plasmid DNA and which enzymatic processes were additionally
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Citation Formats
Klimczak, U.
Strand breaks and lethal damage in plasmid DNA subjected to {sup 60}CO-{gamma}irradiation; Strangbrueche und letale Schaeden in {sup 60}Co-{gamma}-bestrahlter Plasmid-DNA.
Germany: N. p.,
1992.
Web.
Klimczak, U.
Strand breaks and lethal damage in plasmid DNA subjected to {sup 60}CO-{gamma}irradiation; Strangbrueche und letale Schaeden in {sup 60}Co-{gamma}-bestrahlter Plasmid-DNA.
Germany.
Klimczak, U.
1992.
"Strand breaks and lethal damage in plasmid DNA subjected to {sup 60}CO-{gamma}irradiation; Strangbrueche und letale Schaeden in {sup 60}Co-{gamma}-bestrahlter Plasmid-DNA."
Germany.
@misc{etde_10129120,
title = {Strand breaks and lethal damage in plasmid DNA subjected to {sup 60}CO-{gamma}irradiation; Strangbrueche und letale Schaeden in {sup 60}Co-{gamma}-bestrahlter Plasmid-DNA}
author = {Klimczak, U}
abstractNote = {Experiments with calf thymus DNA subjected to extracellular irradiation yield information on the role of direct and indirect effects in single-strand breakage, if this is evaluated with reference to the scavenger activity in respect of OH radicals. The role of the two processes in the occurrence of double-stand breaks and further damage leading to cell decay has so far remained largely obscure. It was the aim of the study described here to contribute to research in this field by performing in vitro experiments on biologically active DNA. For this purpose, DNA from pBR322 plasmids was irradiated in the presence of OH-radical scavengers. The number of single-strand and double-strand breaks was determined on the basis of the system`s ability to eliminate OH radicals. In order to asses the influence of irradiation processes on the biological activity of DNA, investigations were carried out in E. coli for transformations caused by irradiated plasmid DNA. The results were interpreted in the light of theories about inhomogenous reaction kinetics put forward by Mark et al. (1989). It was finally discussed, which of the gamma-irradiation injuries occurring in DNA was to be held responsible for the inactivation of plasmid DNA and which enzymatic processes were additionally at work here. (orig./MG) [Deutsch] Experimente mit extrazellulaer bestrahlter Kalbsthymus-DNA ermoeglichten Aussagen ueber die Beteiligung von direktem und indirektem Effekt an der Einzelstrangbruchbildung in Abhaengigkeit von der OH-Radikalfaenger-Kapazitaet. Ueber die Beteiligung dieser beiden Prozesse an der Bildung von Doppelstrangbruechen sowie anderer Schaeden, die in der Zelle zu einem letalen Ereignis fuehren, konnten bisher nur begrenzt Aussagen gemacht werden. Ziel der vorliegenden Arbeit war es, durch in vitro-Untersuchungen an biologisch aktiver DNA zur Loesung dieser Problematik beizutragen. Hierzu wurde pBR322 Plasmid-DNA in Gegenwart von OH-Radikalfaengern {gamma}-bestrahlt. Die Menge an Einzel- und Doppelstrangbruechen in der DNA wurde in Abhaengigkeit von der Faehigkeit des Systems, OH-Radikale abzufangen, bestimmt. Der Einfluss der Bestrahlungsvorgaenge auf die biologische Aktivitaet der DNA wurde durch Transformation von E. coli durch bestrahlte Plasmid-DNA untersucht. Zur Interpretation der Ergebnisse wurden die inhomogene Reaktionskinetik von Mark et al. (1989) herangezogen. Abschliessend wurde diskutiert, welcher der durch {gamma}-Bestrahlung an der DNA entstandenen Schaeden zur Inaktivierung der Plasmid-DNA fuehrt und welche enzymatischen Prozesse dabei beteiligt sind. (orig./MG)}
place = {Germany}
year = {1992}
month = {Dec}
}
title = {Strand breaks and lethal damage in plasmid DNA subjected to {sup 60}CO-{gamma}irradiation; Strangbrueche und letale Schaeden in {sup 60}Co-{gamma}-bestrahlter Plasmid-DNA}
author = {Klimczak, U}
abstractNote = {Experiments with calf thymus DNA subjected to extracellular irradiation yield information on the role of direct and indirect effects in single-strand breakage, if this is evaluated with reference to the scavenger activity in respect of OH radicals. The role of the two processes in the occurrence of double-stand breaks and further damage leading to cell decay has so far remained largely obscure. It was the aim of the study described here to contribute to research in this field by performing in vitro experiments on biologically active DNA. For this purpose, DNA from pBR322 plasmids was irradiated in the presence of OH-radical scavengers. The number of single-strand and double-strand breaks was determined on the basis of the system`s ability to eliminate OH radicals. In order to asses the influence of irradiation processes on the biological activity of DNA, investigations were carried out in E. coli for transformations caused by irradiated plasmid DNA. The results were interpreted in the light of theories about inhomogenous reaction kinetics put forward by Mark et al. (1989). It was finally discussed, which of the gamma-irradiation injuries occurring in DNA was to be held responsible for the inactivation of plasmid DNA and which enzymatic processes were additionally at work here. (orig./MG) [Deutsch] Experimente mit extrazellulaer bestrahlter Kalbsthymus-DNA ermoeglichten Aussagen ueber die Beteiligung von direktem und indirektem Effekt an der Einzelstrangbruchbildung in Abhaengigkeit von der OH-Radikalfaenger-Kapazitaet. Ueber die Beteiligung dieser beiden Prozesse an der Bildung von Doppelstrangbruechen sowie anderer Schaeden, die in der Zelle zu einem letalen Ereignis fuehren, konnten bisher nur begrenzt Aussagen gemacht werden. Ziel der vorliegenden Arbeit war es, durch in vitro-Untersuchungen an biologisch aktiver DNA zur Loesung dieser Problematik beizutragen. Hierzu wurde pBR322 Plasmid-DNA in Gegenwart von OH-Radikalfaengern {gamma}-bestrahlt. Die Menge an Einzel- und Doppelstrangbruechen in der DNA wurde in Abhaengigkeit von der Faehigkeit des Systems, OH-Radikale abzufangen, bestimmt. Der Einfluss der Bestrahlungsvorgaenge auf die biologische Aktivitaet der DNA wurde durch Transformation von E. coli durch bestrahlte Plasmid-DNA untersucht. Zur Interpretation der Ergebnisse wurden die inhomogene Reaktionskinetik von Mark et al. (1989) herangezogen. Abschliessend wurde diskutiert, welcher der durch {gamma}-Bestrahlung an der DNA entstandenen Schaeden zur Inaktivierung der Plasmid-DNA fuehrt und welche enzymatischen Prozesse dabei beteiligt sind. (orig./MG)}
place = {Germany}
year = {1992}
month = {Dec}
}