DNA endonuclease activities on psoralen plus ultraviolet light treated DNA
Activities of nuclear DNA endonucleases (Endos) from normal human lymphoblastoid cells on DNA treated with the DNA interstrand cross-linking agents 4,5'8-trimethyl psoralen (TMP) or 8-methoxypsoralen (MOP) plus long-wavelength (320-400 nm) ultraviolet light (UVA) were examined. Chromatin-associated DNA Endos were isolated from both cell lines and subjected to isoelectric focusing (IF). Each IF fraction was assayed for DNA Endo activity. Peaks of activity were pooled and assayed for activity on undamaged PM2 bacteriophage DNA and on PM2 DNA that had been treated with 15 ..mu..g/ml TMP or MOP in the dark and then exposed to UVA light. Unbound psoralen was removed by dialysis and a second dose of UVA light was given in order to increase the number of DNA cross-links. Two Endo activities were found which were active on TMP- and MOP-DNA: a major one, pI 4.6, which is also active on intercalated DNA, and a second, lesser one, pI 7.6, which is active on UVC (254 nm) light irradiated DNA. These results indicate that there are two different DNA Endos which act on both TMP- and MOP-treated DNA and that the major activity recognizes the intercalation of, and/or the cross-link produced by interaction of, psoralen with DNA.
- Research Organization:
- New Jersey Medical School, Newark
- OSTI ID:
- 5416158
- Report Number(s):
- CONF-8604222-; TRN: 86-030543
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
- Country of Publication:
- United States
- Language:
- English
Similar Records
Site specificity of psoralen-DNA interstrand cross-linking determined by nuclease Bal31 digestion
Molecular analysis by electron microscopy of the removal of psoralen-photoinduced DNA cross-links in normal and Fanconi's anemia fibroblasts
Related Subjects
DNA
GENETIC RADIATION EFFECTS
ENDONUCLEASES
ENZYME ACTIVITY
PSORALEN
GENETIC EFFECTS
BACTERIOPHAGES
CROSS-LINKING
ULTRAVIOLET RADIATION
ANTICOAGULANTS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CHEMICAL REACTIONS
COUMARINS
DNA-ASE
DRUGS
ELECTROMAGNETIC RADIATION
ENZYMES
ESTERASES
HEMATOLOGIC AGENTS
HETEROCYCLIC COMPOUNDS
HYDROLASES
MICROORGANISMS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PARASITES
PHOSPHODIESTERASES
POLYMERIZATION
RADIATION EFFECTS
RADIATIONS
VIRUSES
560111* - Radiation Effects on Biochemicals- In Vitro- (-1987)
560301 - Chemicals Metabolism & Toxicology- Cells- (-1987)