homospermidine synthase (spermidine-specific) | |||||||||
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Identifiers | |||||||||
EC no. | 2.5.1.45 | ||||||||
Databases | |||||||||
IntEnz | IntEnz view | ||||||||
BRENDA | BRENDA entry | ||||||||
ExPASy | NiceZyme view | ||||||||
KEGG | KEGG entry | ||||||||
MetaCyc | metabolic pathway | ||||||||
PRIAM | profile | ||||||||
PDB structures | RCSB PDB PDBe PDBsum | ||||||||
Gene Ontology | AmiGO / QuickGO | ||||||||
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In enzymology, a homospermidine synthase (spermidine-specific) (EC 2.5.1.45) is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are spermidine and putrescine, whereas its two products are sym-homospermidine and propane-1,3-diamine.
This enzyme belongs to the family of transferases, specifically those transferring aryl or alkyl groups other than methyl groups. The systematic name of this enzyme class is spermidine:putrescine 4-aminobutyltransferase (propane-1,3-diamine-forming).
Putrescine is an organic compound with the formula (CH2)4(NH2)2. It is a colorless solid that melts near room temperature. It is classified as a diamine. Together with cadaverine, it is largely responsible for the foul odor of putrefying flesh, but also contributes to other unpleasant odors.
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 is a polyamine compound found in ribosomes and living tissues and having various metabolic functions within organisms. It was originally isolated from 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.
Hypusine is an uncommon amino acid found in all eukaryotes and in some archaea, but not in bacteria. The only known proteins containing the hypusine residue is eukaryotic translation initiation factor 5A (eIF-5A) and a similar protein found in archaea. In humans, two isoforms of eIF-5A have been described: eIF5A-1 and eIF5A-2. They are encoded by two distinct genes EIF5A and EIF5A2. The protein is involved in protein biosynthesis and promotes the formation of the first peptide bond. The region surrounding the hypusine residue is highly conserved and is essential to the function of eIF5A. Thus, hypusine and eIF-5A appear to be vital for the viability and proliferation of eukaryotic cells.
Diamine oxidase (DAO), also known "amine oxidase, copper-containing, 1" (AOC1), formerly called histaminase, is an enzyme involved in the metabolism, oxidation, and inactivation of histamine and other polyamines such as putrescine or spermidine. The enzyme belongs to the amine oxidase (copper-containing) (AOC) family of amine oxidase enzymes.
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.
In enzymology, a spermidine dehydrogenase (EC 1.5.99.6) is an enzyme that catalyzes the chemical reaction
In enzymology, a putrescine N-methyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a diamine N-acetyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a sym-norspermidine synthase 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.
A polyamine is an organic compound having more than two amino groups. Alkyl polyamines occur naturally, but some are synthetic. Alkylpolyamines are colorless, hygroscopic, and water soluble. Near neutral pH, they exist as the ammonium derivatives. Most aromatic polyamines are crystalline solids at room temperature.
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
Polyamine oxidase (propane-1,3-diamine-forming) (EC 1.5.3.14, MPAO, maize PAO) is an enzyme with systematic name spermidine:oxygen oxidoreductase (propane-1,3-diamine-forming). This enzyme catalyses the following chemical reaction
Homospermidine synthase (EC 2.5.1.44) is an enzyme with systematic name putrescine:putrescine 4-aminobutyltransferase (ammonia-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.