We report that 3',5'-cyclic CMP undergoes nonenzymatic di- and trimerization at 20 °C under dry conditions upon proton or UV irradiation. The reaction involves stacking of the cyclic monomers and subsequent polymerization through serial transphosphorylations between the stacked monomers. Proton- and UV-induced oligomerization of 3',5'-cyclic CMP demonstrates that pyrimidines-similar to purines-might also have taken part in the spontaneous generation of RNA under plausible prebiotic conditions as well as in an extraterrestrial context. The observed polymerization of naturally occurring 3',5'-cyclic nucleotides supports the possibility that the extant genetic nucleic acids might have originated by way of a straight Occamian path, starting from simple reactions between plausibly preactivated monomers.
- MeSH
- chemické modely MeSH
- cirkulární dichroismus MeSH
- CMP cyklický chemie účinky záření MeSH
- evoluce chemická MeSH
- oligoribonukleotidy chemická syntéza MeSH
- polymerizace MeSH
- protony MeSH
- RNA chemická syntéza MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- ultrafialové záření MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Using biochemical methods, we have examined the effect of two factors that might play a role in the mechanism of the biological activity of cisplatin at elevated temperatures (>37 degrees C). We show that increased temperatures result in distinct alterations in the modification of the target DNA by cisplatin, and in the repair of these modifications. Our in vitro results support the view that the enhanced DNA-cross-linking efficiency of cisplatin and the lower efficiency of native DNA repair mechanisms at higher temperature play at least a partial role in the potentiation of the antitumor effects of cisplatin under conditions of mild hyperthermia.
- MeSH
- časové faktory MeSH
- cisplatina farmakologie chemie MeSH
- DNA řízené RNA-polymerasy antagonisté a inhibitory chemie MeSH
- DNA chemie účinky léků MeSH
- financování organizované MeSH
- HeLa buňky MeSH
- lidé MeSH
- oprava DNA MeSH
- protinádorové látky farmakologie chemie MeSH
- RNA chemická syntéza chemie účinky léků MeSH
- skot MeSH
- teplota MeSH
- vazebná místa MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- skot MeSH
- zvířata MeSH
