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Poly(ADP-ribose)synthetase from HeLa cell nuclei: purification and properties
The Italian Journal of Biochemistry
|May 1, 1987
Summary
Researchers purified poly(ADP-ribose)synthetase from HeLa cells, finding two distinct enzyme forms. Evidence suggests this enzyme can undergo auto-ADP-ribosylation, a key finding for DNA repair research.
Area of Science:
- Biochemistry
- Molecular Biology
- Enzymology
Background:
- Poly(ADP-ribose)synthetase (PARS) is crucial in DNA repair and genomic stability.
- Understanding PARS purification and properties is vital for cellular processes.
Purpose of the Study:
- To purify and characterize poly(ADP-ribose)synthetase from HeLa cell nuclei.
- To investigate the enzyme's dependence on DNA and histones.
- To explore the possibility of enzyme auto-ADP-ribosylation.
Main Methods:
- Enzyme purification using biochemical techniques.
- SDS-PAGE electrophoresis to determine molecular weight.
- Incubation of isolated nuclei with radiolabeled NAD.
Main Results:
- Over 600-fold purification of PARS achieved.
- Two enzyme components identified with apparent molecular weights of 110,000 and 118,000.
- Enzyme activity showed dependence on DNA and modulation by histones.
- Evidence of auto-ADP-ribosylation demonstrated through radioactive labeling.
Conclusions:
- HeLa cell nuclei contain distinct forms of poly(ADP-ribose)synthetase.
- The enzyme's activity is regulated by DNA and histone interactions.
- The study provides further evidence for the auto-ADP-ribosylation of PARS.