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Title: 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.
Authors:
;
Publication Date:
OSTI Identifier:
5416158
Report Number(s):
CONF-8604222-
Journal ID: CODEN: FEPRA; TRN: 86-030543
Resource Type:
Conference
Resource Relation:
Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States); Journal Volume: 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
Research Org:
New Jersey Medical School, Newark
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; 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)