Altered electrophoretic behavior of DNA due to short-time UV-B irradiation.
UV-B irradiation is often inevitable for visualization of DNA fragments after ethidium bromide staining. Three different simple-repeat-containing, double-stranded genomic DNA fragments were analyzed for UV-B (312 nm) damage using different gel electrophoretic systems. The effects of UV-B light were obvious after 5 min (31.5 kJ/m2) of irradiation in native polyacrylamide gel electrophoresis (PAGE). Standard single-strand conformation analyses revealed no alterations while a modification did. Sodium dodecyl sulfate (SDS)-PAGE was found to be highly sensitive with regard to the detection of damages and their time/dosage dependency. In addition, SDS-PAGE analysis pointed to different events occurring during UV-B irradiation. Alterations in DNA conformation were detected in every single strand analyzed after 1 min (6.3 kJ/m2) of UV-B exposure. Gel retardation analyses revealed significant changes of protein binding to target DNAs after 2 min of irradiation--possibly stemming from structural modifications and/or originating from binding sites for proteins involved in DNA repair.
Mäueler
W
W
Molecular Human Genetics, Ruhr University, Bochum, Germany.
Kyas
A
A
Bröcker
F
F
Epplen
J T
JT
D001483:Base Sequence; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects*; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation / Q000528:radiation effects; D011485:Protein Binding / Q000528:radiation effects; D013997:Time Factors; D014466:Ultraviolet Rays
D004268:DNA-Binding Proteins; D004247:DNA