| Literature DB >> 1648406 |
Y Desmarais1, L Ménard, J Lagueux, G G Poirier.
Abstract
We have characterized the effect of poly(ADP-ribose) polymerase automodification on the enzyme's activities, which include poly(ADP-ribose) synthesis and NADase activity. The apparent Km of the enzyme for NAD+ during polymer synthesis is higher than the one measured for alternate NADase activity. Furthermore, we have found that there are 28 automodification sites, in contrast to the 15 sites (postulated to be on the 15 glutamic acids) reported to be present in the automodification domain. For the first time, we show that some of these acceptor sites are outside the reported automodification domain (15 kDa); we demonstrate automodification in the NAD+ binding domain (55.2 kDa) and the DNA binding domain (42.5 kDa). We have analyzed the relationship between the number of sites modified on poly(ADP-ribose) polymerase and its effect on the polymerization activity and its alternate NADase activity. Automodification greatly altered both enzyme activities, decreasing both polymer synthesis and alternate NADase activity.Entities:
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Year: 1991 PMID： 1648406 DOI： 10.1016/0167-4838(91)99007-f
Source DB: PubMed Journal: Biochim Biophys Acta ISSN： 0006-3002