Enzymatic studies of radiation damage. Final report, January 1, 1979-September 30, 1981
The susceptibility of the DNA in chromatin to single-strand specific nucleases was examined using nuclease P/sub 1/, mung beam nuclease, and venom phosphodiesterase. These experiments showed that chromatin contains a limited number of DNA sites which are susceptible to single-strand specific nucleases. These sites occur at intervals of 8 to 80 nucleosomes and are distributed throughout the chromatin. An endogenous nuclease was found in chicken erythrocyte nuclei. This enzyme resembles the nuclease of mammalian nuclei in requirements for bivalent cations and in production of large chromatin fragments that gradually decrease in size, but differs in that the products do not go through the stage of discrete bands on gel electrophoresis. Experiments in which chromatin fragments from micrococcal nuclease digestion were further digested with venom phosphodiesterase indicated that phosphodiesterase perferentially hydrolyzes all linkers, although this preference is not marked enough to produce and preserve particulate structures of chromatin. Analysis of the ribose-containing components resulting from digestion of chromatin by micrococcal nuclease and P/sub 1/ nuclease led to the conclusion that a minimal amount of Poly (ADP-Rib) is necessary to form and preserve the structure of nucleosomes.
- Research Organization:
- New York State Dept. of Health, Buffalo (USA)
- DOE Contract Number:
- AS02-76EV03225
- OSTI ID:
- 5637837
- Report Number(s):
- DOE/EV/03225-44; ON: DE82005478
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
560111* -- Radiation Effects on Biochemicals-- In Vitro-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
CHROMATIN
DECOMPOSITION
DNA
ENZYMATIC HYDROLYSIS
ENZYME ACTIVITY
ENZYMES
ESTERASES
HYDROLASES
HYDROLYSIS
IONS
LYSIS
NUCLEASES
NUCLEIC ACIDS
NUCLEOSOMES
ORGANIC COMPOUNDS
PHOSPHODIESTERASES
SOLVOLYSIS
STRAND BREAKS
VENOMS