Saccharopine

Saccharopine is an intermediate in the metabolism

Metabolism

Metabolism is the set of chemical reactions that occur in living organisms to maintain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories. Catabolism breaks down organic matter,...

 of amino acid lysine

Lysine

Lysine is an α-amino acid with the chemical formula HO₂CCH₄NH₂. This amino acid is an essential amino acid, which means that humans cannot synthesize it. Its codons are AAA and AAG.Lysine is a base, as are arginine and histidine...

. It is a precursor of lysine in the alpha-aminoadipate

Alpha-aminoadipate

α-Aminoadipic acid is an intermediate in the metabolism of lysine and saccharopine.-See also:* Adipic acid...

 pathway which occurs in a few lower fungi

Fungus

A fungus is any member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. The Fungi are classified as a kingdom that is separate from plants, animals and bacteria...

, the higher fungi, and euglenid

Euglenid

The euglenids are one of the best-known groups of flagellates, commonly found in freshwater especially when it is rich in organic materials, with a few marine and endosymbiotic members. Many euglenids have chloroplasts and produce energy through photosynthesis, but others feed by phagocytosis or...

s. In mammals and higher plants saccharopine is an intermediate in the degradation of lysine, formed by condensation of lysine and alpha-ketoglutarate.

Saccharopine is an intermediate in the metabolism

Metabolism

Metabolism is the set of chemical reactions that occur in living organisms to maintain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories. Catabolism breaks down organic matter,...

 of amino acid lysine

Lysine

Lysine is an α-amino acid with the chemical formula HO₂CCH₄NH₂. This amino acid is an essential amino acid, which means that humans cannot synthesize it. Its codons are AAA and AAG.Lysine is a base, as are arginine and histidine...

. It is a precursor of lysine in the alpha-aminoadipate

Alpha-aminoadipate

α-Aminoadipic acid is an intermediate in the metabolism of lysine and saccharopine.-See also:* Adipic acid...

 pathway which occurs in a few lower fungi

Fungus

A fungus is any member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. The Fungi are classified as a kingdom that is separate from plants, animals and bacteria...

, the higher fungi, and euglenid

Euglenid

The euglenids are one of the best-known groups of flagellates, commonly found in freshwater especially when it is rich in organic materials, with a few marine and endosymbiotic members. Many euglenids have chloroplasts and produce energy through photosynthesis, but others feed by phagocytosis or...

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 dehydrogenase

Saccharopine dehydrogenase

Saccharopine dehydrogenase is an enzyme involved in the metabolism of lysine, via saccharopine.It can be classified under , , , and ....

s, are:

lysine + alpha-ketoglutarate <--> saccharopine <--> glutamate + 2-aminoadipate 6-semialdehyde

Pathology

Saccharopinuria

Saccharopinuria

Saccharopinuria , also called saccharopinemia or saccharopine dehydrogenase deficiency, is a variant form of hyperlysinemia caused by a partial deficiency of the enzyme saccharopine dehydrogenase, which plays a secondary role in the lysine metabolic pathway.
...

 (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 (Saccharomyces, hence the name) by Darling and Larsen.