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l-cystine


Name(s) l-cystine
Scientific name(s)
Formula C6H12N2O4S2
Molecular mass 240.3
IUPAC name 2-amino-3-[(2-amino-2-carboxyethyl)disulfanyl]propanoic acid
INCHI InChI=1S/C6H12N2O4S2/c7-3(5(9)10)1-13-14-2-4(8)6(11)12/h3-4H,1-2,7-8H2,(H,9,10)(H,11,12)
SMILE NC(CSSCC(N)C(O)=O)C(O)=O
CAS ID 56-89-3
PubChem ID 67678
DrugBank ID DB00138
CHEBI ID 16283
Description Flavouring ingredient; dietary supplement_x000D_ _x000D_ Cystine is an oxidized dimeric form of cysteine. It is formed by linking two cysteine residues via a disulfide bond (cys-S-S-cys) between the -SH groups. Cystine is found in high concentrations in the cells of the immune system, skeletal and connective tissues, skin, digestive enzymes, and in hair. Hair and skin are 10-14% cystine. Cystine is the preferred form of cysteine for the synthesis of glutathione in cells involved in the immune function including macrophages and astrocytes. Lymphocytes and neurons prefer cysteine for glutathione production. Optimizing glutathione levels in macrophages and astrocytes with cystine allows these cells to provide cysteine to lymphocytes and neurons directly upon demand. (http://en.wikipedia.org/wiki/Cystine); Cystine is the amino acid formed by the oxidation of cysteine molecules to give a disulfide bond. This organosulfur compound has the formula (SCH2CH(NH2)CO2H)2. It is a colorless solid, and melts at 247-249 °C. It was discovered in 1810 by William Hyde Wollaston but was not recognized as being derived of proteins until it was isolated from the horn of a cow in 1899. Through formation of disulfide bonds within and between protein molecules, cystine is a significant determinant of the tertiary structure of most proteins. Disulfide bonding, along with hydrogen bonding and hydrophobic interactions is partially responsible for the formation of the gluten matrix in bread. Human hair contains approximately 5% cystine by mass.; L-Cystine is a covalently linked dimeric nonessential amino acid formed by the oxidation of cysteine. Two molecules of cysteine are joined together by a disulfide bridge to form cystine. Cystine is a chemical substance which naturally occurs as a deposit in the urine, and can form a calculus (hard mineral formation) when deposited in the kidney. The compound produced when two cysteine molecules linked by a disulfide (S-S) bond. Cystine is required for proper vitamin B6 utilization and is also helpful in the healing of burns and wounds, breaking down mucus deposits in illnesses such as bronchitis as well as cystic fibrosis. Cysteine also assists in the supply of insulin to the pancreas, which is needed for the assimilation of sugars and starches. It increases the level of glutathione in the lungs, liver, kidneys and bone marrow, and this may have an anti-aging effect on the body by reducing age-spots etc.