Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1984-7-2
pubmed:abstractText
The activity of purified Ca2+, Mg2+-dependent endonuclease was inhibited when the enzyme was incubated in a system containing poly(ADP-ribose) synthetase, NAD+, Mg2+, and DNA. All four ingredients were essential to mediate ADP-ribosylation and to demonstrate inhibition of the endonuclease. In the absence of Mg2+, ADP-ribose transferring activity of poly(ADP-ribose) synthetase was stimulated by the addition of purified endonuclease to the reaction mixture in a dose-dependent manner. Analysis of the reaction product showed that the endonuclease was ADP-ribosylated. The average chain length of the initial oligo(ADP-ribose) attached to the enzyme was about 5.9 residues. The oligomer was found to be extensively elongated during the chase experiment using unlabeled NAD+ and Mg2+. The present finding suggests that Mg2+ is essential for the extensive elongation of the oligo(ADP-ribose). The DNA-binding affinity of the modified endonuclease was significantly lower than that of unmodified enzyme. Also, free poly(ADP-ribose) was not an effective inhibitor of the endonuclease. These findings suggest that the observed inhibition of the endonuclease induced by ADP-ribosylation is probably due to an electrostatic repulsion between the substrate (DNA) and poly(ADP-ribose) covalently linked to the endonuclease. Histone H1 and H2B stimulated endonuclease activity and were acceptors of ADP-ribose; however, their capacity to stimulate endonuclease activity remained unchanged after ADP-ribosylation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
259
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6579-85
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Mechanism of the inhibition of Ca2+, Mg2+-dependent endonuclease of bull seminal plasma induced by ADP-ribosylation.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't