Enzymatic studies of radiation damage. Progress report, 1977--1978 including the summary for the triennium, 1975--1978. [Enzyme properties of venom phosphodiesterase and molecular structure of chromatin]
It was recently found that venom phosphodiesterase has properties of single-strand specific enzymes; it cleaves circular superhelical DNA and produces a full-length linear DNA (form III) plus a number of discrete bands of fragmented double-stranded DNA. The cleavages that lead to these fragments occur in pairs. Each pair accounts for the total length of the genome. Mapping of fragments showed that 4 out of 5 susceptible sites corresponded to previously established early denaturation sites. Single-strand specific enzymes were studied wich chromatin (chicken erythrocytes) as substrate. Chromatin is reluctantly digested to products of very high molecular weight ranging from 30 to 100 S with an average of about 60 S. Further digestion of these products with micrococcal nuclease leads to nucleosomes suggesting that nucleosomes remain preserved.
- Research Organization:
- Roswell Park Memorial Inst., Buffalo, NY (USA)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 6931068
- Report Number(s):
- COO-3225-35
- Country of Publication:
- United States
- Language:
- English
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