spermine] The polyamines are organic compounds having two or more primary amino groups - such as putrescine, cadaverine, spermidine, and spermine- that are growth factors in both eucaryoticand procaryoticcells. Cyclenis the main representative of a class of cyclic polyamines. Polyethylene amineis a polymerbased on aziridine monomer.
Though it is known that polyamines are synthesized in cells via highly-regulated pathways, their actual function is not entirely clear. As cations, they bind to
DNA, and, in structure, they represent compounds with cations that are found at "regularly-spaced intervals" (unlike, say, Mg++ or Ca++, which are point charges).
If cellular polyamine synthesis is inhibited,
cell growthis stopped or severely retarded. The provision of exogenous polyamines restores the growth of these cells. Most eukaryotic cells have a polyamine transportersystem on their cell membranethat facilitates the internalization of exogenous polyamines. This system is highly active in rapidly proliferating cells and is the target of some chemotherapeutics currently under development. [Wang, C.; Delcros, J.-G.; Cannon, L.; Konate, F.; Carias, H.; Biggerstaff, J.; Gardner, R.; Phanstiel, O. Defining the molecular requirements for the selective delivery of polyamine-conjugates into cells containing active polyamine transporters. J. Med. Chem. 2003, 46, 5129-5138.]
Polyamines are also important modulators of a variety of
ion channels, including NMDA receptors and AMPA receptors. They block inward-rectifier potassium channels so that the currents of the channels are inwardly rectified, thereby the cellular energy, i.e. K+ ion gradient across the cell membrane, is conserved.
ynthesis of linear polyamines
Putrescineis synthesized biologically via two different pathways, both starting from arginine.
* In one pathway, arginine is converted into
agmatine, with a reaction catalyzed by the enzyme arginine decarboxylase(ADC); then agmatine is transformed into carbamilputrescineby agmatine imino hydroxylase(AIH). Finally, carbamilputrescine is converted into putrescine.
* In the second pathway, arginine is converted into
ornithineand then ornithine is converted into putrescine by ornithine decarboxylase(ODC).
Cadaverineis synthesized from lysinein a one-step reaction with lysine decarboxylase(LDC).
permidine and spermine
Spermidineis synthesized from putrescine, using an aminopropylic group from decarboxylated S-adenosyl-L-methionine(SAM). The reaction is catalyzed by spermidine synthase. Spermineis synthesized from the reaction of spermidine with SAM in the presence of the enzyme spermine synthase.
* [http://www.biol.lu.se/zoofysiol/Cellprolif/Research/research_area_1.html Polyamines in cell cycle proliferation and cell death]
* [http://herkules.oulu.fi/isbn9514266315/html/index.html Ornithine Decarboxylase: Expression and regulation in rat brain and in transgenic mice, 2002, Pekka Kilpelainen, Department of Biochemistry, University of Oulu. Extensive review of literature through 2001 on polyamine structure, properties, metabolism in mammals, and physiological and pathophysiological roles (See article Table of Contents)]
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polyamine — [ pɔliamin ] n. f. • 1898; de poly et amine ♦ Chim., biol. Substance aliphatique linéaire possédant plusieurs fonctions amine. ● polyamine nom féminin Composé chimique renfermant plusieurs fonctions amine. polyamine n. f. CHIM Corps possédant… … Encyclopédie Universelle
Polyamine — Unter Polyamine werden meist gesättigte, offenkettige oder cyclische organische Verbindungen zusammenfasst, mit endständigen Aminogruppen, unterbrochen von einer wechselnden Anzahl sekundärer Aminogruppen. Polyamine sind je nach Kettenlänge… … Deutsch Wikipedia
Polyamine — Putrescine ou diaminobutane, une polyaamine qui participe à donner aux cadavres en décomposition leur odeur. Les polyamines sont des composés organiques possédant deux ou plusieurs fonctions amine. Parmi les composés répondant à cette définition … Wikipédia en Français
polyamine — “+ noun Etymology: International Scientific Vocabulary poly + amine : a compound characterized by more than one amino group * * * /pol ee euh meen , am in/, n. Chem. a compound containing more than one amino group. [1860 65; POLY + AMINE] * * *… … Useful english dictionary
polyamine — noun Date: 1861 a compound characterized by more than one amino group … New Collegiate Dictionary
polyamine — Polycations at physiological pH, polyamines can bind and interact with various other molecules within the cell. In particular interact with DNA but also may modulate ion channels and act as growth factors. Spermine has four positive charges,… … Dictionary of molecular biology
polyamine — /pol ee euh meen , am in/, n. Chem. a compound containing more than one amino group. [1860 65; POLY + AMINE] * * * … Universalium
polyamine — noun any compound having many (more than three) amino functional groups … Wiktionary
polyamine — Class name for substances of the general formula H2N(CH2)nNH2, H2N(CH2)nNH(CH2)nNH2, H2N(CH2)nNH(CH2)nNH(CH2)nNH2, where n = 3, 4, or 5. Many polyamines arise by bacterial … Medical dictionary
polyamine — n. compound containing more than one of the amino acid groups (Chemistry) … English contemporary dictionary