Spermine is a polyamine involved in cellular metabolism that is found in all eukaryotic cells. The precursor for synthesis of spermine is the amino acid ornithine. It is an essential growth factor in some bacteria as well. It is found as a polycation at physiological pH. Spermine is associated with nucleic acids and is thought to stabilize helical structure, particularly in viruses. It functions as an intracellular free radical scavenger to protect DNA from free radical attack. Spermine is the chemical primarily responsible for the characteristic odor of semen.
Spermidine synthase is an enzyme that catalyzes the transfer of the propylamine group from S-adenosylmethioninamine to putrescine in the biosynthesis of spermidine. The systematic name is S-adenosyl 3-(methylthio)propylamine:putrescine 3-aminopropyltransferase and it belongs to the group of aminopropyl transferases. It does not need any cofactors. Most spermidine synthases exist in solution as dimers.
In molecular biology, the protein domain Saccharopine dehydrogenase (SDH), also named Saccharopine reductase, is an enzyme involved in the metabolism of the amino acid lysine, via an intermediate substance called saccharopine. The Saccharopine dehydrogenase enzyme can be classified under EC 1.5.1.7, EC 1.5.1.8, EC 1.5.1.9, and EC 1.5.1.10. It has an important function in lysine metabolism and catalyses a reaction in the alpha-Aminoadipic acid pathway. This pathway is unique to fungal organisms therefore, this molecule could be useful in the search for new antibiotics. This protein family also includes saccharopine dehydrogenase and homospermidine synthase. It is found in prokaryotes, eukaryotes and archaea.
Spermine synthase is an enzyme that converts spermidine into spermine. This enzyme catalyses the following chemical reaction
In enzymology, a putrescine N-methyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a secologanin synthase (EC 1.14.19.62, was wrongly classified as EC 1.3.3.9 in the past) is an enzyme that catalyzes the chemical reaction
In enzymology, a reticuline oxidase (EC 1.21.3.3) is an enzyme that catalyzes the chemical reaction
In enzymology, a senecionine N-oxygenase (EC 1.14.13.101) is an enzyme that catalyzes the chemical reaction
In enzymology, a cholestenol Δ-isomerase is an enzyme that catalyzes the chemical reaction
UDP-sulfoquinovose synthase (EC 3.13.1.1) is an enzyme that catalyzes the chemical reaction
In enzymology, a glutathionylspermidine synthase is an enzyme that catalyzes the chemical reaction
In enzymology, a homospermidine synthase (spermidine-specific) is an enzyme that catalyzes the chemical reaction
Deoxyhypusine synthase is an enzyme that in humans is encoded by the DHPS gene.
Senecionine is a toxic pyrrolizidine alkaloid isolated from various botanical sources. It takes its name from the Senecio genus and is produced by many different plants in that genus, including Jacobaea vulgaris. It has also been isolated from several other plants, including Brachyglottis repanda, Emilia, Erechtites hieraciifolius, Petasites, Syneilesis, Crotalaria, Caltha leptosepala, and Castilleja.
Carboxynorspermidine synthase (EC 1.5.1.43, carboxynorspermidine dehydrogenase, carboxyspermidine dehydrogenase, CASDH, CANSDH) is an enzyme with systematic name carboxynorspermidine:NADP+ oxidoreductase. This enzyme catalyses the following chemical reactions
N1-acetylpolyamine oxidase (EC 1.5.3.13, hPAO-1, mPAO, hPAO) is an enzyme with systematic name N1-acetylpolyamine:oxygen oxidoreductase (3-acetamidopropanal-forming). This enzyme catalyses the following chemical reaction
Non-specific polyamine oxidase (EC 1.5.3.17, polyamine oxidase, Fms1, AtPAO3) is an enzyme with systematic name polyamine:oxygen oxidoreductase (3-aminopropanal or 3-acetamidopropanal-forming). This enzyme catalyses the following chemical reaction
Deoxyhypusine synthase (EC 2.5.1.46, spermidine:eIF5A-lysine 4-aminobutyltransferase (propane-1,3-diamine-forming)) is an enzyme with systematic name (eIF5A-precursor)-lysine:spermidine 4-aminobutyltransferase (propane-1,3-diamine-forming). This enzyme catalyses the following chemical reaction
Thomas Hartmann,, was a German pharmaceutical biologist and ecologist who was professor in the Department of Pharmaceutical Biology at the Technische Universität Braunschweig. His research focused on the biosynthesis, intracellular transport, and action of quinolizidine and pyrrolizidine alkaloids in fungi and plants and the sequestration of these secondary natural products by insects.
Monocrotaline (MCT) is a pyrrolizidine alkaloid that is present in plants of the Crotalaria genus. These species can synthesise MCT out of amino acids and can cause liver, lung and kidney damage in various organisms. Initial stress factors are released intracellular upon binding of MCT to BMPR2 receptors and elevated MAPK phosphorylation levels are induced, which can cause cancer in Homo sapiens. MCT can be detoxified in rats via oxidation, followed by glutathione-conjugation and hydrolysis.
