Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.4.2.30 (PARP)
13,611 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Incubation of membranes of human promyelocytic leukemia HL-60 cells with [32P]NAD led to ADP-ribosylation of several proteins including a 38 kDa protein by endogenous ADP-ribosyltransferases. The ADP-ribosylation of the 38 kDa protein was distinctly different from others on the basis of pH dependency and heat stability at 50 degrees C, suggesting that there are at least two endogenous ADP-ribosyltransferases. It was enhanced by CTP, but not affected by ATP, GTP and UTP, whereas it was inhibited by GTP gamma S. [alpha-32P]CTP bound to the 38 kDa protein immobilized on a nitrocellulose sheet, indicating that the 38 kDa protein which bound CTP is strongly ADP-ribosylated by an endogenous ADP-ribosyltransferase.
...
PMID:CTP-dependent endogenous ADP-ribosylation of a 38 kDa protein in HL-60 cell membranes. 212 32

The 22 kDa protein substrate of botulinum ADP-ribosyltransferase C3 was purified from porcine brain cytosol by acetone precipitation, CM-Sephadex, octyl-Sepharose and TSK phenyl-5PW HPLC chromatography to apparent homogeneity. ADP-ribosylation of the protein was increased by guanine nucleotides (GTP, GDP, GTP gamma S, each 100 microM) but not by GMP, ATP or ATP gamma S. The purified 22 kDa protein bound maximally 0.9 mol [35S]GTP gamma S and hydrolyzed GTP with the rate 0.007 mol per mol protein. Amino acid sequences were obtained from two tryptic peptides, selected from an in situ digestion of Immobilon electrotransferred, gel purified ADP-ribosylated substrate. The two sequences obtained, cover 23 residues from the corresponding sequences in human rho.
...
PMID:Purification of the 22 kDa protein substrate of botulinum ADP-ribosyltransferase C3 from porcine brain cytosol and its characterization as a GTP-binding protein highly homologous to the rho gene product. 249 91

The mechanism by which MgADP stimulates the activity of dinitrogenase reductase ADP-ribosyltransferase (DRAT) has been examined by using dinitrogenase reductases from Rhodospirillum rubrum, Klebsiella pneumoniae, and Azotobacter vinelandii as acceptor substrates. In the presence of 0.2 mM NAD, maximal rates of ADP-ribosylation of all three acceptors were observed at an ADP concentration of 150 microM; in the absence of added ADP, DRAT activity with the dinitrogenase reductases from R. rubrum and K. pneumoniae was less than 5% of the maximal rate, but the A. vinelandii protein was ADP-ribosylated at 40% of the maximal rate. Of eight dinucleotides tested, only ADP, 2'-deoxy-ADP, and ADP-beta S served as activators of the DRAT reaction; ADP, 2'-deoxy-ADP, and ADP-beta S were also the only dinucleotides found which inhibited acetylene reduction activity by dinitrogenase reductase. The dinucleotide specificities for both DRAT activation and acetylene reduction inhibition were the same for all three dinitrogenase reductases. In the DRAT reaction with the dinitrogenase reductases from K. pneumoniae and A. vinelandii, the Km for NAD was 30-fold higher in the absence of ADP than in its presence; the Km for NAD with the R. rubrum acceptor was not measurable. In the presence of saturating ADP, ADP-ribosylation of dinitrogenase reductase from R. rubrum was inhibited 63% by 1.5 mM ATP. It is concluded that MgADP stimulates DRAT activity by lowering the Km for NAD and that MgADP exerts its effect by binding to dinitrogenase reductase. MgATP inhibits DRAT activity by competing with MgADP for binding to dinitrogenase reductase.
...
PMID:Effect of nucleotides on the activity of dinitrogenase reductase ADP-ribosyltransferase from Rhodospirillum rubrum. 250 83

Clostridium spiroforme iotalike toxin produced time- and concentration-dependent incorporation of ADP-ribose into homo-poly-L-arginine. Polyasparagine, polyglutamic acid, polylysine, and agmatine were poor substrates. Enzyme activity was associated with the light-chain polypeptide of the toxin. The heavy chain did not possess ADP-ribosyltransferase activity, nor did it enhance or inhibit activity of the light chain. In broken-cell assays, the toxin acted mainly on G-actin, rather than F-actin. A single ADP-ribose group was transferred to each substrate molecule (G-actin). The enzyme was heat sensitive, had a pH optimum in the range of 7 to 8, was inhibited by high concentrations of nicotinamide, and was reversibly denatured by urea and guanidine. Physiological levels of nucleotides (AMP, ADP, ATP, and ADP-ribose) and cations (Na+, K+, Ca2+, and Mg2+) were not very active as enzyme inhibitors. The toxin was structurally and functionally similar to Clostridium botulinum type C2 toxin and Clostridium perfringens iota toxin. When combined with previous findings, the data suggest that a new class of mono(ADP-ribosyl)ating toxins has been found and that these agents belong to a related and possibly homologous series of binary toxins.
...
PMID:Production by Clostridium spiroforme of an iotalike toxin that possesses mono(ADP-ribosyl)transferase activity: identification of a novel class of ADP-ribosyltransferases. 252 Dec 14

H2O2, in concentrations achieved in the proximity of stimulated leukocytes, induces injury and lysis of target cells. This may be an important aspect of inflammatory injury of tissues. Cell lysis in two target cells, the murine macrophage-like tumor cell line P388D1 and human peripheral lymphocytes, was found to be associated with activation of poly(ADP-ribose) polymerase (EC 2.4.2.30), a nuclear enzyme. This enzyme is activated under various conditions of DNA damage. Poly(ADP-ribose) polymerase utilizes nicotinamide adenine dinucleotide (NAD) as substrate and has been previously shown to consume NAD during exposure of cells to oxidants that was associated with inhibition of glycolysis, a decrease in cellular ATP, and cell death. In the current studies, inhibition of poly(ADP-ribose) polymerase by 3-aminobenzamide, nicotinamide, or theophylline in cells exposed to lethal concentrations of H2O2 prevented the sequence of events that eventually led to cell lysis--i.e., the decrease in NAD, followed by depletion of ATP, influx of extracellular Ca2+, actin polymerization and, finally, cell death. DNA damage, the initial stimulus for poly(ADP-ribose) polymerase activation, occurred despite the inhibition of this enzyme. Cells exposed to oxidant in the presence of the poly(ADP-ribose) polymerase inhibitor 3-aminobenzamide failed to demonstrate repair of DNA strand breaks.
...
PMID:Hydrogen peroxide-induced injury of cells and its prevention by inhibitors of poly(ADP-ribose) polymerase. 294 60

The ADP-ribosylation site of histone H1 from calf thymus by purified hen liver nuclear ADP-ribosyltransferase was determined and effects of the ADP-ribose X histone-H1 adduct on cAMP-dependent phosphorylation of the histone H1 were investigated. ADP-ribosylated histone H1 was prepared by incubation of histone H1, 1 mM [adenylate-32P]NAD and the purified ADP-ribosyltransferase. N-Bromosuccinimide-directed bisection of ADP-ribosylated histone H1 showed that the NH2-terminal fragment (Mr = 6000) was modified and contained serine residue 38, the site of phosphorylation by cAMP-dependent protein kinase. Digestion of the NH2-terminal fragment with cathepsin D and trypsin, and purification of this fragment, using high-performance liquid chromatography, yielded a radiolabelled single peptide corresponding to residues 29-34 of histone H1, containing the arginine residue as the ADP-ribosylation site. These results indicate that ADP-ribosylation of histone H1 occurs at the arginine residue 34, sequenced at the NH2-terminal side of the phosphate-accepting serine residue 38. Phosphorylation of histone H1 from calf thymus by cAMP-dependent protein kinase was markedly reduced when histone H1 was ADP-ribosylated. Kinetic studies of phosphorylation revealed that ADP-ribosylated histone H1 was a linear competitive inhibitor of histone H1 and a linear non-competitive inhibitor of ATP.
...
PMID:Amino acid sequence of histone H1 at the ADP-ribose-accepting site and ADP-ribose X histone-H1 adduct as an inhibitor of cyclic-AMP-dependent phosphorylation. 299 55

Bordetella pertussis, the causative agent of whooping cough, releases pertussis toxin in an inactive form. The toxin consists of an A protomer containing one S1 peptide subunit and a B oligomer containing several other peptide subunits. The toxin binds to cells via the B oligomer, and the S1 subunit is activated and expresses ADP-ribosyltransferase and NAD glycohydrolase activities. Treatment of purified toxin with dithiothreitol (DTT) in vitro increases both activities. ATP and the detergent 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS) synergistically reduce the A0.5 (activation constant) for DTT from greater than 100 mM to 200 microM. We studied the structure-activity relationships of activators of the toxin. In the presence of CHAPS (1%) and DTT (10 mM) the following compounds increased the NAD glycohydrolase activity of the toxin with the following A0.5's in microM and fraction of the ATP effect in parentheses: ATP, 0.2 (1.0); ADP, 6 (0.8); UTP, 15 (0.7); GTP, 35 (0.6); pyrophosphate, 45 (0.7); triphosphate, 60 (0.6); tetraphosphate, greater than or equal to 170 (greater than or equal to 0.4). Thus, the polyphosphate moiety is sufficient to stimulate the toxin, and the adenosine moiety confers upon ATP its extraordinary affinity for the toxin. Phospholipid and detergents could substitute for CHAPS in the activation of the toxin. Glutathione substituted for DTT with an A0.5 of 2 mM, a concentration within the range found in eucaryotic cells. Thus, membrane lipids and cellular concentrations of glutathione and ATP are sufficient to activate pertussis toxin without the need for a eucaryotic enzymatic process.
...
PMID:Structure-activity analysis of the activation of pertussis toxin. 303 Mar 99

The interaction of nucleotides with pertussis toxin (PT), and their effects on the ability of the toxin to ADP-ribosylate pure Ni, were evaluated. [32P]ATP (10 nM) bound directly to dithiothreitol-activated PT. This binding was competitively inhibited by nucleotides and anions with the following IC50 concentrations in order of decreasing potency: ATP = ATP gamma S (adenosine-5'-O-(3-thiotriphosphate)) = 0.2-0.3 microM, GDP beta S (guanosine-5'-O-(2-thiodiphosphate)) = 2-3 microM, GTP gamma S (guanosine-5'-O-(3-thiotriphosphate)) = 10-15 microM, ADP = 20-25 microM, GTP = 30-40 microM, GMP-P(NH)P (guanyl-5'-yl imidodiphosphate) = 100-150 microM, GDP = 150-200 microM, Pi = SO4(2-) = 20 mM and Cl- = acetate = 30-35 mM. Treatment of PT with ATP, AMP-P(NH)P, GTP, GDP, or GDP beta S, resulted in a stimulated state of NAD+-Ni ADP-ribosyltransferase activity. Addition of ATP, AMP-P(NH)P (adenyl-5'-yl imidodiphosphate), GTP, GDP, and GDP beta S to the ADP-ribosylation reactions resulted in increased rates of ADP-ribosyl-Ni formation. It is concluded that these effects on the nucleotides are due to their action to stimulate the activity of PT. At concentrations of PT between 0.04 and 0.4 microgram/ml, the stimulation of ADP-ribosylation of Ni effected by nucleotides was hysteretic in nature, exhibiting an approximately 25-min long lag when GDP was used as the activating nucleotide. These lags decreased with increasing concentrations of PT, and were abolished by pretreatment of the toxin with GDP or ATP. Preliminary incubation of Ni with GDP had no effect on the lag in its ADP-ribosylation by non-nucleotide treated PT. Addition of divalent cations (Mg2+, Mn2+, and Ca2+) inhibited formation of ADP-ribosyl-Ni, possibly by causing aggregation and denaturation of Ni. This is the first demonstration that both adenine and guanine nucleotides interact directly with PT and act to stimulate its activity to ADP-ribosylate Ni, and that guanine nucleotides do so regardless of whether they are nucleoside di- or triphosphates.
...
PMID:The interaction of nucleotides with pertussis toxin. Direct evidence for a nucleotide binding site on the toxin regulating the rate of ADP-ribosylation of Ni, the inhibitory regulatory component of adenylyl cyclase. 309 44

The effect of the addition of guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S), the GTP analog which activates the inhibitory guanine nucleotide-binding regulatory protein of adenylyl cyclase (Ni), on the pertussis toxin-mediated ADP-ribosylation reaction was studied in detail. Two effects were discerned: a stimulation of the ADP-ribosyltransferase activity of the toxin, akin to what was described for ATP and GDP in a previous report (Mattera, R., Codina, J., Sekura, R., and Birnbaumer, L. (1986) J. Biol. Chem. 261, 11173-11179), and a decrease in the ability of Ni to be a substrate for the activated toxin. Both effects were time-dependent with activation of the toxin being somewhat faster than inactivation of Ni. The effect of the addition of GTP gamma S on Ni was readily reversed by excess GDP and attenuated by increasing EDTA in the medium from 0.35 to 10 mM, suggesting dependence on trace concentrations of a divalent cation. It is suggested that this cation is Mg2+ on the basis that low (5-10 nM) concentrations of Mg2+ are needed for the endogenous GTPase activity of Ni (Sunyer, T., Codina, J., and Birnbaumer, L. (1984) J. Biol. Chem. 259, 15447-15451). Sucrose density gradient analysis of the Ni X GTP gamma S complexes with decreased susceptibility to ADP-ribosylation by pertussis toxin showed the same sedimentation parameters as Ni or Ni X GDP complexes, indicating that the molecule of Ni with GTP gamma S bound is heterotrimetric as opposed to dissociated into alpha i X GTP gamma S plus beta X gamma. Thus, these experiments define two conformations of heterotrimeric Ni: one -pt+, ADP-ribosylated by pertussis toxin, and the other pt-, poorly or not ADP-ribosylated by pertussis toxin. This latter, hitherto unrecognized conformation, is stabilized by the addition of strongly activating guanine nucleotides such as GTP gamma S and guanyl-5'-yl imidodiphosphate and should be important in the train of events that lead from an inactive heterotrimeric Ni to a fully active and dissociated Ni.
...
PMID:Guanosine 5'-O-(3-thiotriphosphate) reduces ADP-ribosylation of the inhibitory guanine nucleotide-binding regulatory protein of adenylyl cyclase (Ni) by pertussis toxin without causing dissociation of the subunits of Ni. Evidence of existence of heterotrimeric pt+ and pt- conformations of Ni. 311 55

A novel ADP-ribosyltransferase C3 was purified to homogeneity from filtrates of certain strains of Clostridium botulinum type C by ammonium sulfate precipitation, gel filtration, ion-exchange chromatography and heat treatment. The molecular mass of botulinum ADP-ribosyltransferase C3 was found to be 25 kDa. In the presence of [32P]NAD but not with [carbonyl-14C]NAD, C3 labelled 21-24-kDa protein(s) in membranes of human platelets and other tissues. The Km value of the ADP-ribosylation reaction for NAD was about 2 microM. Labelling of the 21-24-kDa protein(s) by C3 was largely reduced by addition of nicotinamide. Snake venom phosphodiesterase cleaved the ADP-ribose attached to the 21-24-kDa protein(s) by C3 and released 5'AMP. C3 catalyzed hydrolysis of [carbonyl-14C]NAD and released [carbonyl-14C]nicotinamide. ADP-ribosylation of 21-24-kDa platelet membrane protein(s) was biphasically regulated by Mg2+, Mn2+ and Ca2+. In the absence of free divalent cations GTP, GTP[gamma S] and GDP but not GDP[beta S], GMP, ATP or ATP[gamma S] increased labelling by C3. In the presence of Mg2+, GTP[gamma S] was inhibitory. Guanine nucleotides prevented heat inactivation of the substrate protein(s) with the rank order GTP[gamma S] = GTP = GDP greater than GDP[beta S] greater than GMP much greater than ATP = GMP = ATP[gamma S]. The data support the view that the novel ADP-ribosyltransferase C3 modifies eukaryotic 21-24-kDa GTP-binding protein(s).
...
PMID:Botulinum ADP-ribosyltransferase C3. Purification of the enzyme and characterization of the ADP-ribosylation reaction in platelet membranes. 312 9


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---