Spermine is a polyamine involved in cellular metabolism that is found in all

eukaryotic cells Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bact ...

. 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

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...

es. Antonie van Leeuwenhoek first described crystals of spermine phosphate in human semen in 1678. The name ''spermin'' was first used by the German chemists Ladenburg and Abel in 1888, and the correct structure of spermine was not finally established until 1926, simultaneously in England (by Dudley, Rosenheim, and Starling) and Germany (by Wrede et al.). Spermine is the chemical primarily responsible for the characteristic odor of semen.

Derivative

derivative In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. ...

of spermine, N¹, N¹²-bis(ethyl)spermine (also known as BESm) was investigated in the late 1980s along with similar polyamine analogues for its potential as a cancer therapy.

Biosynthesis

Spermine biosynthesis in animals starts with decarboxylation of ornithine by the enzyme Ornithine decarboxylase in the presence of PLP. This decarboxylation gives

putrescine 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 ...

. Thereafter the

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

spermidine synthase 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- ...

effects two N-alkylation by decarboxy- S-Adenosyl methionine. The intermediate is spermidine. Plants employ additional routes to spermine. In one pathway L-glutamine is the precursor to L-ornithine, after which the synthesis of spermine from L-ornithine follows the same pathway as in animals. Polyamine synthesis

Another pathway in plants starts with decarboxylation of L-arginine to produce agmatine. The imine functional group in agmatine then is hydrolysed by

agmatine deiminase In enzymology, an agmatine deiminase () is an enzyme that catalyzes the chemical reaction :agmatine + H2O \rightleftharpoons N-carbamoylputrescine + NH3 Thus, the two substrates of this enzyme are agmatine and H2O, whereas its two products are ...

, releasing

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous ...

, converting the guanidine group into a urea. The resulting N-carbamoylputrescine is acted on by a hydrolase to split off the urea group, leaving

. After that the putrescine follows the same pathway to completing the synthesis of spermine.

Derivative

Biosynthesis

References

Further reading