INVESTIGADORES
HOZBOR Daniela Flavia
artículos
Título:
Photoinduced cleavage of plasmid DNA in the presence of pterin
Autor/es:
LORENTE C; THOMAS A; VILLATA LS; HOZBOR D; LAGARES A; CAPPARELLI A
Revista:
PTERIDINES
Editorial:
INT SOC PTERIDINOLOGY
Referencias:
Año: 2000 p. 100 - 105
ISSN:
0933-4807
Resumen:
The photoinduced cleavage of plasmid DNA by UV -A light in the presence
of pterin was investigated. Electrophoretic analysis of the irradiated
plasmid pUCI8 in the presence of pterin showed that UV light of 350 nm
induced the transformation of a significant proportion of the
supercoiled plasmid to its relaxed form. A minor proportion of plasmid
forms are also converted to the linear plasmid isomer at the longer
irradiation times. All these transformations during irradiation can be
observed in the absorption spectrum of DNA as function of time. Such
spectral modifications correlated with the extent and the kinetics of
plasmid relaxation, but not with the appearance of the linear plasmid.
None of the exchanges were operative without the irradiation with UV-A
light. Control experiments with pterin or plasmid DNA irradiated
separately, showed no photochemical changes. Results taken together
suggest that the observed changes in the supercoiled plasmid as well as
the spectral modifications both derive from the generation of
single-strand break in the DNA.
