scholarly journals Effect of analogues of 5′-methylthioadenosine on cellular metabolism. Inactivation of S-adenosylhomocysteine hydrolase by 5′-isobutylthioadenosine

1983 ◽  
Vol 210 (2) ◽  
pp. 429-435 ◽  
Author(s):  
F Della Ragione ◽  
A E Pegg
Keyword(s):  
Convenient Method ◽  
Cellular Metabolism ◽  
Spermidine Synthase ◽  
Polyamine Synthesis ◽  
Adenosylhomocysteine Hydrolase ◽  
Methylthioadenosine Phosphorylase ◽  
Spermine Synthase ◽  
Irreversible Inhibition

The effects of a number of nucleosides related to 5′-methylthioadenosine on the activities of S-adenosylhomocysteine hydrolase, 5′-methylthioadenosine phosphorylase, spermidine synthase and spermine synthase were investigated. Both 5′-methylthioadenosine and 5′-isobutylthioadenosine gave rise to an enzyme-activated irreversible inhibition of S-adenosylhomocysteine hydrolase, but 5′-methylthiotubercidin (5′-methylthio-7-deaza-adenosine), 5′-deoxy-5′-chloroformycin, 5′-ethylthio-2-fluoro-adenosine and 1,N6-etheno-5′-methylthioadenosine were totally ineffective in producing this inactivation. Of the nucleosides tested, only 5′-methylthioadenosine, 5′-methylthiotubercidin and 5′-isobutylthioadenosine were inhibitory towards the aminopropyltransferases responsible for the synthesis of spermine and spermidine. 5′-Methylthiotubercidin, 5′-deoxy-5′-chloroformycin and 5′-isobutylthioadenosine were inhibitors of the degradation of 5′-methylthioadenosine by 5′-methylthioadenosine phosphorylase, but only 5′-isobutylthioadenosine was also a substrate for this enzyme. These results suggest that the effects of 5′-isobutylthioadenosine of the cell may result from the combination of inhibitory actions on polyamine synthesis, 5′-methylthioadenosine degradation and S-adenosylhomocysteine degradation. The resulting increased concentrations of S-adenosylhomocysteine could bring about inhibition of methyltransferase reactions. A new convenient method for the assay of S-adenosylhomocysteine hydrolase in the direction of synthesis is described.

Effects of inhibitors of spermidine synthase and spermine synthase on polyamine synthesis in rat tissues

1993 ◽  
Vol 45 (9) ◽  
pp. 1897-1903 ◽  
Author(s):  
Akira Shirahata ◽  
Norio Takahashi ◽  
Takanobu Beppu ◽  
Harumi Hosoda ◽  
Keijiro Samejima
Keyword(s):  
Rat Tissues ◽  
Spermidine Synthase ◽  
Polyamine Synthesis ◽  
Spermine Synthase

scholarly journals Studies of inhibition of rat spermidine synthase and spermine synthase

1980 ◽  
Vol 187 (2) ◽  
pp. 419-428 ◽  
Author(s):  
Hiroshige Hibasami ◽  
Ronald T. Borchardt ◽  
Shiang Yuan Chen ◽  
James K. Coward ◽  
Anthony E. Pegg
Keyword(s):  
Amino Acid ◽  
Ventral Prostate ◽  
Amino Group ◽  
Spermidine Synthase ◽  
Polyamine Synthesis ◽  
Weak Inhibitor ◽  
Spermine Synthase ◽  
Rat Ventral Prostate ◽  
Potential Inhibitors ◽  
Derivatives Of

1. S-Adenosyl-l-methionine, S-adenosyl-l-homocysteine, 5′-methylthioadenosine and a number of analogues having changes in the base, sugar or amino acid portions of the molecule were tested as potential inhibitors of spermidine synthase and spermine synthase from rat ventral prostate. 2. S-Adenosyl-l-methionine was inhibitory to these reactions, as were other nucleosides containing a sulphonium centre. The most active of these were S-adenosyl-l-ethionine, S-adenosyl-4-methylthiobutyric acid, S-adenosyl-d-methionine and S-tubercidinylmethionine, which were all comparable in activity with S-adenosylmethionine itself, producing 70–98% inhibition at 1mm concentrations. Spermine synthase was somewhat more sensitive than spermidine synthase. 3. 5′-Methylthioadenosine, 5′-ethylthioadenosine and 5′-methylthiotubercidin were all powerful inhibitors of both enzymes, giving 50% inhibition of spermine synthase at 10–15μm and 50% inhibition of spermidine synthase at 30–45μm. 4. S-Adenosyl-l-homocysteine was a weak inhibitor of spermine synthase and practically inactive against spermidine synthase. Analogues of S-adenosylhomocysteine lacking either the carboxy or the amino group of the amino acid portion were somewhat more active, as were derivatives in which the ribose ring had been opened by oxidation. The sulphoxide and sulphone derivatives of decarboxylated S-adenosyl-l-homocysteine and the sulphone of S-adenosyl-l-homocysteine were quite potent inhibitors and were particularly active against spermidine synthase (giving 50% inhibition at 380, 50 and 20μm respectively). 5. These results are discussed in terms of the possible regulation of polyamine synthesis by endogenous nucleosides and the possible value of some of the inhibitory substances in experimental manipulations of polyamine concentrations. It is suggested that 5′-methylthiotubercidin and the sulphone of S-adenosylhomocysteine or of S-adenosyl-3-thiopropylamine may be particularly valuable in this respect.

scholarly journals Inhibition of the synthesis of polyamines and macromolecules by 5′-methylthioadenosine and 5′-alkylthiotubercidins in BHK21 cells

1982 ◽  
Vol 204 (3) ◽  
pp. 697-703 ◽  
Author(s):  
Aarne Raina ◽  
Kyllikki Tuomi ◽  
Raija-Leena Pajula
Keyword(s):  
Growth Inhibition ◽  
Spermidine Synthase ◽  
Baby Hamster Kidney ◽  
Polyamine Synthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Spermine Synthase ◽  
Target Sites ◽  
Polyamine Content ◽  
Exogenous Spermidine

5′-Methylthioadenosine and four 5′-alkylthiotubercidins were tested for their ability to inhibit polyamine synthesis in vitro and to decrease polyamine concentration and prevent growth of baby-hamster-kidney (BHK21) cells. 5′-Methylthioadenosine and 5′-methylthiotubercidin decreased the activity of spermidine synthase from brain to roughly the same extent, whereas brain spermine synthase was much more strongly inhibited by 5′-methylthioadenosine compared with 5′-methylthiotubercidin. These nucleoside derivatives also inhibited the growth of BHK21 cells and increased the concentration of putrescine. 5′-Methylthioadenosine decreased cellular spermine concentration, whereas 5′-methylthiotubercidin lowered the concentration of spermidine. The activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase were enhanced in cells grown in the presence of 5′-methylthiotubercidin. The growth inhibition produced by these nucleoside derivatives was not reversed by exogenous spermidine or spermine. 5′-Ethylthiotubercidin, 5′-propylthiotubercidin and 5′-isopropylthiotubercidin did not appreciably inhibit spermidine or spermine synthase in vitro or decrease the cellular polyamine content, but effectively prevented the growth of BHK21 cells. All nucleoside derivatives at concentrations of 0.2–1 mm caused a rapid inhibition of protein synthesis. It is concluded that the growth inhibition produced by 5′-methylthioadenosine and 5′-alkylthiotubercidins was not primarily due to polyamine depletion but other target sites, for instance the cellular nucleotide pool, cell membranes etc. must be considered.

scholarly journals Response of enzymes involved in the metabolism of polyamines to phytohaemagglutinin-induced activation of human lymphocytes

1981 ◽  
Vol 196 (3) ◽  
pp. 733-738 ◽  
Author(s):  
H Korpela ◽  
E Hölttä ◽  
T Hovi ◽  
J Jänne
Keyword(s):  
Ornithine Decarboxylase ◽  
Human Lymphocytes ◽  
Lymphocyte Activation ◽  
Decarboxylase Activity ◽  
Spermidine Synthase ◽  
Irreversible Inhibitor ◽  
Adenosylmethionine Decarboxylase ◽  
Spermine Synthase ◽  
Diamine Oxidase Activity ◽  
Stimulation Of

The stimulation of lymphocyte ornithine decarboxylase and adenosylmethionine decarboxylase produced by phytohaemagglutinin was accompanied by an equally marked, but delayed, stimulation of spermidine synthase, which is not commonly considered as an inducible enzyme. In contrast with the marked stimulation of these biosynthetic enzymes, less marked changes were observed in the biodegradative enzymes of polyamines in response to phytohaemagglutinin. Diamine oxidase activity was undetectable during all stages of the transformation. The activity of polyamine oxidase remained either constant or was slightly decreased several days after addition of the mitogen. The activity of polyamine acetylase (employing all the natural polyamines as substrates) distinctly increased both in the cytosolic and crude nuclear preparations of the cells during later stages of mitogen activation. Difluoromethylornithine, an irreversible inhibitor of ornithine decarboxylase, although powerfully inhibiting ornithine decarboxylase, produced a gradual enhancement of adenosylmethionine decarboxylase activity during lymphocyte activation, without influencing the activities of the two propylamine transferases (spermidine synthase and spermine synthase).

Effects of certain 5'-substituted adenosines on polyamine synthesis: selective inhibitors of spermine synthase

Biochemistry ◽  
1986 ◽  
Vol 25 (14) ◽  
pp. 4091-4097 ◽  
Author(s):  
Anthony E. Pegg ◽  
James K. Coward ◽  
Ratnakar R. Talekar ◽  
John A. Secrist
Keyword(s):  
Selective Inhibitors ◽  
Polyamine Synthesis ◽  
Spermine Synthase

scholarly journals Purification and partial characterization of human polyamine synthases

1989 ◽  
Vol 259 (3) ◽  
pp. 879-886 ◽  
Author(s):  
E O Kajander ◽  
L I Kauppinen ◽  
R L Pajula ◽  
K Karkola ◽  
T O Eloranta
Keyword(s):  
Gel Electrophoresis ◽  
Cross Reactivity ◽  
Specific Pattern ◽  
Native Enzyme ◽  
Spermidine Synthase ◽  
Enzyme Preparations ◽  
Spermine Synthase ◽  
Apparent Homogeneity ◽  
Gradient Gel Electrophoresis ◽  
Pore Gradient

Spermidine synthase was purified to apparent homogeneity from human spleens (8700-fold) by affinity chromatography. The native enzyme was composed of two subunits of identical Mr (35,000) and showed an apparent Mr of 62,000 in pore-gradient gel electrophoresis. Its pI was 5.1, Spermine synthase was purified to apparent homogeneity from placenta (5300-fold) and from kidney (4600-fold). The native enzyme was composed of two subunits of identical Mr (45,000) and showed an apparent Mr of 78,000 in pore-gradient gel electrophoresis. In isoelectric focusing it revealed two bands, with pI values of 4.9 and 5.0. Both synthases were present in all human tissues studied, but revealed a clear tissue-specific pattern. Mouse antisera against spermidine synthase revealed only one band, of Mr 35,000, in all purified enzyme preparations and in crude human tissue extracts in immunoblotting. Antisera against spermine synthase showed an immunoreactive band corresponding to the Mr of the subunit of spermine synthase. These antisera did not indicate any cross-reactivity in immunoblotting. Thus spermine synthase and spermidine synthase do not share homologous antigenic sites and are totally different proteins.

scholarly journals Kinetic properties of spermine synthase from bovine brain

1983 ◽  
Vol 215 (3) ◽  
pp. 669-676 ◽  
Author(s):  
R L Pajula
Keyword(s):  
Initial Velocity ◽  
Substrate Inhibition ◽  
Product Inhibition ◽  
Bovine Brain ◽  
Kinetic Properties ◽  
Methylthioadenosine Phosphorylase ◽  
Spermine Synthase ◽  
Michaelis Constants ◽  
Inhibition Studies ◽  
Competitive Product

A kinetic analysis including initial-velocity and product-inhibition studies were performed with spermine synthase purified from bovine brain. The enzyme activity was assayed in the presence of 5′-methylthioadenosine phosphorylase as an auxiliary enzyme to prevent the accumulation of the inhibitory product, 5′-methylthioadenosine, and thus to obtain linearity of the reaction with time. Initial-velocity studies gave intersecting or converging linear double-reciprocal plots. No substrate inhibition by decarboxylated S-adenosylmethionine was observed at concentrations up to 0.4 mM. Apparent Michaelis constants were 60 microM for spermidine and 0.1 microM for decarboxylated S-adenosylmethionine. Spermine was a competitive product inhibitor with respect to decarboxylated S-adenosylmethionine, but a mixed one with respect to the other substrate, spermidine. 5′-Methylthioadenosine showed a mixed inhibition with both substrates, predominantly competitive with respect to decarboxylated S-adenosylmethionine and predominantly uncompetitive with respect to spermidine. The observed kinetic and inhibition patterns are consistent with a compulsory-order mechanism, where both substrates add to the enzyme before products can be released.

scholarly journals The mechanism of opiorphin-induced experimental priapism in rats involves activation of the polyamine synthetic pathway

2009 ◽  
Vol 297 (4) ◽  
pp. C916-C927 ◽  
Author(s):  
Nirmala Devi Kanika ◽  
Moses Tar ◽  
Yuehong Tong ◽  
Dwaraka Srinivasa Rao Kuppam ◽  
Arnold Melman ◽  
...  
Keyword(s):  
Life Stage ◽  
Polyamine Oxidase ◽  
Spermidine Synthase ◽  
Rt Pcr ◽  
Direct Role ◽  
Polyamine Synthesis ◽  
Synthetic Pathway ◽  
Adenosylmethionine Decarboxylase ◽  
Background Strain ◽  
Arginase I

Intracorporal injection of plasmids encoding opiorphins into retired breeder rats can result in animals developing a priapic-like condition. Microarray analysis demonstrated that following intracorporal gene transfer of plasmids expressing opiorphins the most significantly upregulated gene in corporal tissue was the ornithine decarboxylase gene (ODC). Quantitative RT-PCR confirmed the upregulation of ODC, as well as other genes involved in polyamine synthesis, such as arginase-I and -II, polyamine oxidase, spermidine synthase, spermidine acetyltransferase (SAT), and S-adenosylmethionine decarboxylase. Western blot analysis demonstrated upregulation of arginase-I and -II, ODC, and SAT at the protein level. Levels of the polyamine putrescine were upregulated in animals treated with opiorphin-expressing plasmids compared with controls. A direct role for the upregulation of polyamine synthesis in the development of the priapic-like condition was supported by the observation that the ODC inhibitor 1,3-diaminopropane, when added to the drinking water of animals treated with plasmids expressing opiorphins, prevented experimental priapism. We also demonstrate that in sickle cell mice, another model of priapism, there is increased expression of the mouse opiorphin homologue in corporal tissue compared with the background strain at a life stage prior to evidence of priapism. At a life stage when there is onset of priapism, there is increased expression of the enzymes involved in polyamine synthesis (ODC and arginase-I and -II). Our results suggest that the upregulation of enzymes involved in the polyamine synthetic pathway may play a role in the development of experimental priapism and represent a target for the prevention of priapism.

Sign in / Sign up

Export Citation Format

Share Document