Poly synthetase human placenta

Poly(ADP-ribose) synthetases were purified from calf thymus [4], mouse testis [5], and human placenta [6]. Proteolytic digestion was performed as described previously [7, 8]. 3-(Bromoacetyl)pyridine was prepared according to the method of Woenckhaus... 

Poly(ADP-ribose) synthetases were purified to apparent homogeneity from calf thymus, mouse testis, and human placenta. The major characteristics of these enzymes are presented in Table 1. In addition to molecular mass, sedimentation constant, isoelectric point, and partial specific volume, the apparent for NAD and DNA as well as V ,ax of the reaction are all common to these three enzymes. Amino acid compositions of the enzymes are shown in Table 2. Here again, the numbers of each amino acid residue are very similar to each other, although some differences as denoted by star symbols are noted. 

Poly(ADP-ribose) synthetase is a chromatin-bound enzyme which, in the presence of DNA, catalyzes polymerization of the ADP-ribose moiety of NAD to form a protein-bound homopolymer, poly(ADP-ribose) (1). The enzyme is automodified during the reaction. It has been shown that the enzyme consists of three functional domains for DNA-binding, automodification, and NAD-binding (2-4). The enzyme has recently been purified from human placenta and characterized (4, 5). To study the structure and function of the enzyme in more detail we have prepared monoclonal antibodies to the placental enzyme (6, 7). The present study defines three monoclonal antibodies to human poly(ADP-ribose) synthetase and shows that one of the antibodies which binds to the NAD binding domain inhibits the enzyme activity. 

Fig. 3. Immunoblot of poly(ADP-ribose) synthetase recognized by monoclonal antibodies. Purified poly(ADP-ribose) synAetase and human placenta extract were resolved by SDS-polyacrylamide gel electrophoresis on a 7.5% acrylamide gel, and transferred to nitrocellulose membranes. A, gel stained with Ooomassie blue B-D, strips incubated with monoclonal antibodies G6, D4, and X3, respectively. Bound antibodies were detected by the peroxidase-antiperoxidase technique as describe (4).

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