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Biomedical subjects

S Tanuma

Publications and source records attributed to S Tanuma.

At least 73 records · Page 4Linked to original sources
PubMed1991

Change in activity of nuclear poly(ADP-ribose) glycohydrolase during the HeLa S3 cell cycle.

The change in activity of nuclear poly(ADP-ribose) glycohydrolase during the cell cycle of HeLa S3 cells was investigated. The poly(ADP-ribose) glycohydrolase activity was solubilized from HeLa S3 cell nuclei and chromosomes only by sonication at high ionic strength. The enzyme hydrolyzed poly(ADP-ribose) exoglycosidically, producing ADP-ribose. After release from mitosis, the activity of the solubilized nuclear poly(ADP-ribose) glycohydrolase per nucleus or per unit protein, assayed with [3H]poly(ADP-ribose) (average chain length, n = 15) as substrate, was lowest in the early G1 phase and highest in the late G1 phase. The specific activity in the late G1 phase was about two times that in the early G1 phase. The high activity remained constant during the S-G2-M phase. A similar change during the cell cycle was observed after release from hydroxyurea block. These results suggest that the activity of poly(ADP-ribose) glycohydrolase doubled during the G1 phase of the cell cycle of HeLa S3 cells.

Cell Cycle↗
PubMed1991

Stimulation of human peripheral blood polymorphonuclear cell iodination by lignin-related substances.

Lignin is a heterogenous natural product composed of phenylpropane units and is usually associated with hemicellulose in its native state. Until now little attention has been paid to the potential therapeutic utility of lignified products. Natural lignified products are demonstrated in the present study to stimulate iodination significantly (incorporation of radioactive iodine into an acid-insoluble fraction) of human peripheral blood polymorphonuclear cells (PMN). This stimulation was significantly inhibited in the presence of myeloperoxidase inhibitors. These materials were almost completely deprived of their stimulation capacity by treatment with NaCIO2, but this capacity was not affected by severe treatment with H2SO4 or trifluoroacetic acid. Similar stimulating activity by chemically defined tannin-related polyphenolic compounds was observed. Degradation products or component units of lignin, and natural antitumor polysaccharides and their chemically modified derivatives (introduced with negatively or positively charged groups) and polysialoglycoproteins had little or no activity. The results indicate the importance of a polymerized phenolic structure for the stimulation of PMN iodination. Possible physiological relevance of the stimulation of iodination by lignified substances is discussed.

Antineoplastic Agents↗
PubMed1991

Effects of chemically defined tannins on poly (ADP-ribose) glycohydrolase activity.

Three classes of chemically defined tannins, gallotannins, ellagitannins and condensed tannins were examined for their inhibitory activities against purified poly (ADP-ribose) glycohydrolase. Ellagitannins showed higher inhibitory activities than gallotannins. In contrast, condensed tannins, which consist of an epicathechin gallate (ECG) oligomer without a glucose core were not appreciably inhibitory. Kinetic analysis revealed that the inhibition of ellagitannins was competitive with respect to the substrate poly(ADP-ribose), whereas gallotannins exhibited mixed-type inhibition. These results suggest that conjugation with glucose of hexahydroxy-diphenoyl (HHDP) group, which is a unique component of ellagitannins, potentiated the inhibitory activity, and that the structure of ellagitannins may have a functional domain which competes with poly(ADP-ribose) on the poly(ADP-ribose) glycohydrolase molecule.

Glycoside Hydrolases↗
PubMed1990

Purification and characterization of an (ADP-ribose)n glycohydrolase from human erythrocytes.

An (ADP-ribose)n glycohydrolase from human erythrocytes was purified approximately 13,000-fold and characterized. On sodium dodecyl sulfate/polyacrylamide gel the purified enzyme appeared homogeneous and had an estimated relative molecular mass (Mr) of 59,000. Amino acid analysis showed that the enzyme had a relatively high content of acidic amino acid residues and low content of basic amino acid residues. Isoelectrofocusing showed that the enzyme was an acidic protein with pI value of 5.9. The mode of hydrolysis of (ADP-ribose)n by this enzyme was exoglycosidic, yielding ADP-ribose as the final product. The Km value for (ADP-ribose)n (average chain length, n = 15) was 5.8 microM and the maximal velocity of its hydrolysis was 21 mumol.min-1.mg protein-1. The optimum pH for enzyme activity was 7.4 KCl was more inhibitory than NaCl. The enzyme activity was inhibited by ADP-ribose and cAMP but not the dibutyryl-derivative (Bt2-cAMP), cGMP or AMP. These physical and catalytic properties are similar to those of cytosolic (ADP-ribose)n glycohydrolase II, but not to those of nuclear (ADP-ribose)n glycohydrolase I purified from guinea pig liver [Tanuma, S., Kawashima, K. & Endo, H. (1986) J. Biol. Chem. 261, 965-969]. Thus, human erythrocytes contain (ADP-ribose)n glycohydrolase II. The kinetics of degradation of poly(ADP-ribose) bound to histone H1 by purified erythrocyte (ADP-ribose)n glycohydrolase was essentially the same as that of the corresponding free poly(ADP-ribose). In contrast, the glycohydrolase showed appreciable activity of free oligo(ADP-ribose), much less activity on the corresponding oligo(ADP-ribose) bound to histone H1. The enzyme had more activity on oligo(ADP-ribose) bound to mitochondrial and cytosolic free mRNA ribonucleoprotein particle (mRNP) proteins than on oligo(ADP-ribose) bound to histone H1. It did not degrade mono(ADP-ribosyl)-stimulatory guanine-nucleotide-binding protein (Gs) and -inhibitory guanine-nucleotide-binding protein (Gi) prepared with cholera and pertussis toxins, respectively. These results suggest that cytosolic (ADP-ribose)n glycohydrolase II may be involved in extranuclear de(ADP-ribosyl)n-ation, but not in membrane de-mono(ADP-ribosyl)ation.

Adenosine Diphosphate Ribose↗
PubMed1990

Identification in human erythrocytes of mono(ADP-ribosyl) protein hydrolase that cleaves a mono(ADP-ribosyl) Gi linkage.

A novel enzymatic activity, the hydrolysis of linkages between mono(ADP-ribose) and cysteine residues in Gi prepared by eukaryotic ADP-ribosyltransferase C [(1988) J. Biol. Chem. 263, 5485-5489] was found in the cytosol of human erythrocytes. The mono(ADP-ribosyl) Gi hydrolase, tentatively named ADP-ribosyl protein hydrolase C was partially purified by sequential chromatographies on DEAE-cellulose and Blue Sepharose. This enzyme catalyzes the release of ADP-ribose from mono(ADP-ribosyl) Gi. Its activity was enhanced by Ca2+ and inhibited by ADP-ribose. The presence of this enzyme in eukaryotic cells suggests that endogenous mono(ADP-ribosyl)ation of Gi is a reversible post-translational modification.

Adenosine Diphosphate Ribose↗
PubMed1989

Evidence for a novel metabolic pathway of (ADP-ribose)n: pyrophosphorolysis of ADP-ribose in HeLa S3 cell nuclei.

ADP-ribose liberated from (ADP-ribose)n by the action of (ADP-ribose)n glycohydrolase was converted to ATP and ribose 5-phosphate (ribose 5-P) in the presence of pyrophosphate (PPi) in HeLa S3 cell nuclei. This reaction was reversible and dependent on the simultaneous presence of ADP-ribose, PPi, Mg2+, and nuclei. These results suggest the presence of a novel enzyme in the nuclei, designated as ADP-ribose pyrophosphorylase, which catalyzes the reaction shown in Equation 1. ADP-ribose + PPi in equilibrium ATP + Ribose 5-P (1) This reaction could represent a pathway for the biosynthesis of ATP from (ADP-ribose)n in eukaryotic cell nuclei.

Adenosine Diphosphate Ribose↗
PubMed1989

Mono(ADP-ribosyl)ation of Gi by eukaryotic cysteine-specific mono(ADP-ribosyl) transferase attenuates inhibition of adenylate cyclase by epinephrine.

Eukaryotic cysteine-specific mono(ADP-ribosyl)transferase, named ADP-ribosyltransferase C (Tanuma, S., Kawashima, K. and Endo, H. (1988) J. Biol. Chem. 263, 5485-5489), attenuates inhibition of adenylate cyclase in human platelet membranes by epinephrine. This attenuation appeared to result from mono(ADP-ribosyl)ation by ADP-ribosyltransferase C of the inhibitory guanine nucleotide-binding protein (Gi) of adenylate cyclase. These results indicate a role of ADP-ribosyltransferase C in regulation of hormonal control of the adenylate cyclase system.

ADP Ribose Transferases↗
PubMed1989

Lignin inhibits (ADP-ribose)n glycohydrolase activity.

(ADP-ribose)n glycohydrolase activity was inhibited in vitro by lignin, a naturally occurring polymethoxyphenolic compound. However, coniferyl alcohol, which is a main component of lignin, was not inhibitory even at 100 micrograms/ml. Lignin caused competitive inhibition with respect to the substrate (ADP-ribose)n and its Ki value was 18 micrograms/ml. These results suggest that lignin with a polymerized structure has a functional domain that interacts with the (ADP-ribose)n glycohydrolase molecule at the same site as (ADP-ribose)n.

Binding, Competitive↗
PubMed1989

Inhibitory effect of tannin on poly(ADP-ribose) glycohydrolase from human placenta.

Tannin, a naturally occurring polyphenolic compound, was found to inhibit the activity of purified poly(ADP-ribose) glycohydrolase from human placenta. The inhibition was dose-dependent and half maximal with 2.8 micrograms/ml of tannin. The inhibitory effect of tannin was two and three orders of magnitude more than those of ADP-ribose and cAMP, respectively. Kinetic analysis revealed that the inhibition by tannin was competitive with respect to the substrate poly(ADP-ribose).

Binding Sites↗
PubMed1988

Eukaryotic mono(ADP-ribosyl)transferase that ADP-ribosylates GTP-binding regulatory Gi protein.

An NAD:cysteine ADP-ribosyltransferase designated ADP-ribosyltransferase C was purified approximately 35,000-fold from human erythrocytes with an 11% yield. The purified ADP-ribosyltransferase C exhibited one predominant protein band on sodium dodecyl sulfate-polyacrylamide gels with an estimated molecular weight (Mr) of 28,500. The Km values for NAD and cysteine methyl ester were determined to be 65 and 4,400 microM, respectively. By using human erythrocyte inside-out membrane vesicles, the transferase C was found to ADP-ribosylate the alpha subunit (Mr = 41,000) of Gi, which is a substrate for pertussis toxin. The ADP-ribosylation of Gi alpha catalyzed by ADP-ribosyltransferase C was inhibited by pre-ADP-ribosylation with pertussis toxin. The linkage of ADP-ribose-Gi alpha in the membranes formed by ADP-ribosyltransferase C was as stable to hydroxylamine as that formed by pertussis toxin. These data represent the first demonstration that eukaryotic cells contain an ADP-ribosyltransferase which can catalyze the ADP-ribosylation of a cysteine residue in Gi alpha.

ADP Ribose Transferases↗
PubMed1987

Evidence of a regulatory role of the level of poly (ADP-ribose) in chromosomal proteins in metallothionein gene expression by glucocorticoids but not by heavy metals.

The induction capacity of dexamethasone, a synthetic glucocorticoid, for the synthesis of metallothionein was about the same as that of 3-aminobenzamide, which is an inhibitor of ADP-ribosylation of chromosomal proteins, in cultured mouse mammary tumor cells. Both inductions of metallothionein were temporally correlated with a decrease in the amount of endogenous poly (ADP-ribose) on nonhistone high-mobility-group 14 and 17 proteins. In contrast, the extent of cadmium-induced metallothionein synthesis was 2-3-times that of dexamethasone or 3-aminobenzamide. However, cadmium had essentially no effect on de-ADP-ribosylation of these proteins.

Animals↗
PubMed1987

An NAD:cysteine ADP-ribosyltransferase is present in human erythrocytes.

A novel enzymatic activity, i.e., the catalysis of the formation of ADP-ribosylcysteine, was found in the cytosol of human erythrocytes. The NAD:cysteine ADP-ribosyltransferase was partially purified by sequential chromatographic steps on phenyl-Sepharose, phosphocellulose, and Sepharose CL-6B. The enzyme has an apparent molecular weight of 27,000 +/- 3,000, as determined by gel permeation. The formation of ADP-ribosylcysteine was associated with the stoichiometric release of nicotinamide from NAD. The enzyme was found to be highly specific toward cysteine and cysteine methyl ester as ADP-ribose acceptors. S-Benzoyl-L-cysteine, cystine, histidine, glutamic acid, arginine, arginine methyl ester, and agmatine were ineffective as acceptors for this enzyme.

Adenosine Diphosphate↗
PubMed1987

Early changes in parathyroid hormone response and proteoglycan synthesis of chick embryonic femur produced by exposure to 6-aminonicotinamide in ovo.

The mechanism of induction of micromelia in 6-day-old chick embryo by 6-aminonicotinamide (6-AN) was investigated. Six-day-old chick embryo exposed to 6-AN did not show micromelia when tenfold excess of nicotinamide over 6-AN was co-administered. The ability of nicotinamide to prevent the induction of micromelia was partially offset after 4 hr of exposure to 6-AN and completely disappeared after 6 hr. The length of time necessary for the induction of micromelia was not affected by the concentration of 6-AN. These results indicate that exposure to 6-AN for only a short period of 6 hr is sufficient to commit the limb to micromelia and that cellular components involved in the induction of micromelia alter during this period. During this period, newly synthesized proteoglycan monomers typical of cartilage decreased in average molecular size, and isolated femora did not respond to parathyroid hormone (PTH) but to dibutyryl cyclic AMP to stimulate growth of cartilage in organ culture.

6-Aminonicotinamide↗