Saccharopine is an intermediate in the
metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...
of amino acid
lysine
Lysine (symbol Lys or K) is an α-amino acid that is a precursor to many proteins. It contains an α-amino group (which is in the protonated form under biological conditions), an α-carboxylic acid group (which is in the deprotonated &minu ...
. It is a precursor of lysine in the
alpha-aminoadipate pathway which occurs in
fungi
A fungus (plural, : fungi or funguses) is any member of the group of Eukaryote, eukaryotic organisms that includes microorganisms such as yeasts and Mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified ...
and
euglenid
Euglenids (euglenoids, or euglenophytes, formally Euglenida/Euglenoida, ICZN, or Euglenophyceae, ICBN) are one of the best-known groups of flagellates, which are excavate eukaryotes of the phylum Euglenophyta and their cell structure is typical ...
s. In mammals and higher plants saccharopine is an intermediate in the degradation of lysine, formed by condensation of lysine and
alpha-ketoglutarate.
Reaction
The reactions involved, catalysed by
saccharopine dehydrogenases, are:
:lysine + alpha-ketoglutarate ⇌ saccharopine ⇌ glutamate +
2-aminoadipate 6-semialdehyde
Allysine is a derivative of lysine, used in the production of elastin and collagen. It is produced by the actions of the enzyme lysyl oxidase in the extracellular matrix and is essential in the crosslink formation that stabilizes collagen and ela ...
Pathology
Saccharopinuria (high amounts of saccharopine in the urine) and saccharopinemia (an excess of saccharopine in the blood) are conditions present in some inherited disorders of lysine degradation.
History
Saccharopine was first isolated in 1961 from
yeasts
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitut ...
(''Saccharomyces'', hence the name) by Darling and Larsen.
[Darling, S., and Larsen, P. O., Saccharopine, a new amino acid in Baker's and Brewer's yeast: I. Isolation and properties. ''Acta Chem. Scand.'', 15, 743 (1961).]
See also
*
Opines
Opines are low molecular weight compounds found in plant crown gall tumors or hairy root tumors produced by pathogenic bacteria of the genus ''Agrobacterium'' and '' Rhizobium''. Opine biosynthesis is catalyzed by specific enzymes encoded by ge ...
References
{{amino acid metabolism intermediates
Tricarboxylic acids