Images (1)
Cystine (inci)
Synonym(s)
DefinitionThis section has been translated automatically.
Cystine (this usually refers to L-cystine), a disulfide of cysteine, is a natural, proteinogenic amino acid. It occurs in high concentrations, peptide-bound, mainly in skin and hair. Cystine is formed by oxidation of 2 L-cysteine residues. The disulfide bridges (see structural formula) contribute to the stability of tertiary structures.
L-cystine is a white crystalline powder, insoluble in water and water, the disulfide is easily soluble in alkaline lye and mineral acids.
Cystine is contained up to 17 % in the keratin and is connected there via disulfide bridges.
Thus, keratin (from hair, bristles or feathers) contains about 11 % peptide-bound L-cystine. There are also kidney stones which consist of L-cystine.
General informationThis section has been translated automatically.
Cystine is mainly produced by fermentation using genetically modified bacteria of the Escherichia coli type.
Furthermore, cystine can be obtained by hydrolysis of keratin-containing proteins (poultry feathers, hair).
L-cystine is widely used in the food industry.
L-cystine as well as various cystine compounds are used in cosmetic formulations.
Dicapryl cystine is a preparation which, like dimethyl cystinate (INCI), is effective as an antistatic agent in hair cosmetics.
L-Cystine (INCI) also has an antistatic effect (reduces static electricity by neutralizing the electrical charge on the surface of skin and hair); it is also used as a hair conditioner (makes hair easy to comb, smooth, soft and shiny and gives it volume).