cystine

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Related to L-cystine: L-Glutamic Acid

cystine

 [sis´tēn, sis´tin]
a naturally occurring amino acid, the chief sulfur-containing component of the protein molecule. It is sometimes found in the urine and in the kidneys in the form of minute hexagonal crystals, frequently forming cystine calculus in the bladder.
cystine storage disease Fanconi's syndrome (def. 2).

cys·tine

(sis'tēn, sis'tin), Do not confuse this word with cysteine.
3,3'-Dithiobis(2-aminopropionic acid); the disulfide product of two cysteines in which two -SH groups become one -S-S- group; if two cysteinyl residues in polypeptide chains form a disulfide linkage, then the two polymers are cross-linked; sometimes occurs as a deposit in the urine, or forming a vesical calculus. Compare: meso-cystine.
Synonym(s): dicysteine

cystine

/cys·tine/ (sis´tēn) (sis´tin) a sulfur-containing amino acid produced by digestion or acid hydrolysis of proteins, sometimes found in the urine and kidneys, and readily reduced to two molecules of cysteine.

cystine

(sĭs′tēn′)
n.
A white crystalline amino acid, C6H12N2O4S2, that is formed from the disulfide linkage of two cysteines during the folding of many proteins, especially keratin, and stabilizes the tertiary structure of the protein.

cystine

[sis′tin]
a compound consisting of two cysteine residues joined by a disulfide (S-S) linkage. Compare cysteine.
enlarge picture
Chemical structure of cystine

cys·tine

(sis'tēn)
The disulfide product of two cysteines in which two -SH groups become one -S-S- group; sometimes occurs as a deposit in the urine, or forming a vesical calculus.
Cystineclick for a larger image
Fig. 127 Cystine . Formation of cystine.

cystine [Cys-Cys]

an amino acid residue formed by the OXIDATION of the sulphydryl groups [SH] of two CYSTEINES generating a DISULPHIDE BRIDGE (S-S); See Fig. 127 . In some PROTEINS, side chains can be cross-linked by disulphide bridges as a result of the formation of cystines. See SULPHUR BRIDGE.

cystine

a naturally occurring amino acid, an important sulfur-containing component of the protein molecule. It is sometimes found in the urine and in the kidneys in the form of minute hexagonal crystals, frequently forming cystine calculus in the bladder.
Enlarge picture
Cystine stones. By permission from Nelson RW, Couto CG, Small Animal Internal Medicine, Mosby, 2003

cystine calculi
see cystine uroliths.
References in periodicals archive ?
Because common colds can lead to serious complications in elderly and immune-compromised individuals, (21) scientists set out to determine if L-theanine and L-cystine, could also reduce the incidence of the common cold.
For the placebo-controlled study, 176 healthy men were asked to take a total of 700 milligrams of L-cystine and 280 milligrams L-theanine per day, in two divided doses.
Over a five-week period, the L-theanine and L-cystine group developed 58% fewer colds than the placebo group.
The study team reported that, together, L-theanine and L-cystine represent an effective and safe natural ingredient to suppress the common cold--producing no more side effects than placebo.
However, when taken together for two weeks prior to vaccination, the amino acids L-theanine and L-cystine boost the efficacy of the flu vaccine in certain elderly subjects by enhancing the immune system itself.
Taken together for two weeks prior to vaccination, the amino acids L-theanine and L-cystine enhance efficacy of the flu vaccine in a subset of elderly subjects.