L-cystine definition of L-cystine in the Free Online Encyclopedia.

cystine: see cysteine cysteine , organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of mammalian protein.
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cystine [′si‚stēn]

(biochemistry)

C₆H₁₂N₂S₂A white, crystalline amino acid formed biosynthetically from cysteine.

Cystine

(also known as β,β’-dithio-di-α-aminopropionic acid), [HOOCCH(NH₂)CH₂S]₂, a sulfur-containing amino acid; a disulfide of cysteine. Cystine exists as two optically active forms— D-cystine and L-cystine—and two optically inactive forms— DL-cystine and wieso-cystine. L-cystine is a component of almost all natural proteins and peptides. Hair and wool keratin contain up to 18 percent cystine (together with cysteine). The covalent disulfide (—S—S—) bonds formed by cystine residues between and within individual polypeptide chains maintain a definite three-dimensional molecular structure for proteins and biologically active peptides. The retention of disulfide bonds is a requisite for the characteristic properties of fibrous proteins, such as keratins, as well as for the normal activity of various hormones, such as oxytocin, vasopressin, and insulin, and for various enzymes, such as ribonuclease and chymotrypsin. Cystine is a non-essential amino acid. Its biosynthesis and metabolism in organisms are closely linked to cysteine, since cystine and cysteine readily interconvert in living organisms.

A hereditary disturbance of cystine metabolism leads to the development in childhood of cystinosis, a disease in which cystine crystals are deposited in the tissues, causing various problems. The increased excretion of cystine in urine—cystinuria—leads in severe cases to the formation of cystine calculi, from which cystine was first isolated in 1810.

E. N. SAFONOVA

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No references found	The new drink, which contains citric acid, malic acid, L-cystine, phytic acid and methylsulfonylmethane (MSM), helps eliminate poisonous metals from the body while promoting adequate hydration. Ako Kasei to Bring to Market New Functional Soft Drink for Metal ... by JCNN News Summaries the new lychee-flavored beverage contains chelate compounds such as L-cystine, malic acid, methylsulfonylmethane and phytic acid, discharging poisonous metals from the body. Akokasei to Market New Functional Beverage Toru-Tohru Water by JCNN News Summaries	L'Allegro L'Amour, Louis L'Anse aux Meadows L'Aquila L'Assommoir L'Enfant, Pierre Charles L'Enfant, Pierre-Charles L'Engle, Madeleine L'Esperance, Elise l'Hôpital's cubic l'Hôpital's rule L'Hôpital, Michel de l'Huilier's equation L'Olonnois, François L'Ouverture, Toussaint L-1 test L-2 test L-3 test L-4 test L-5 test L-band L-beam L-column L-commerce L-cystathionine L-cystine L-dopa L-fucopyranose L-fucose L-galactomethylose L-head L-head engine L-iron L-plan L-plate l-process L-rhodeose L-shore L-Soft L/D ratio L/M Lža L0 L0pht L1 cache l10n L2 cache L2CAP L2F L2TP L3 cache	L-carnatine L-carnatine L-carnitine L-carnitine L-carnitine L-carnitine L-Carnitine L-Tartrate L-carnosine L-carnosine L-chain L-chain L-chain L-CHEAPO L-CL L-column L-commerce L-CPMET L-CSA L-Curve L-cystathionine L-cysteine L-cysteine L-cysteine L-cysteine hydrochloride L-cysteine hydrochloride L-cysteine hydrochloride L-cysteine hydrochloride monohydrate L-cysteine hydrochloride monohydrate L-cysteine hydrochloride monohydrate L-Cysteine Methyl Ester L-cystine L-D L-D converter L-D-TD L-deprenyl L-dopa L-dopa L-dopa L-driver L-drivers L-electron capture L-electron capture L-electron capture L-enantiomer L-enantiomer L-enantiomer L-FABP L-fields L-Fold Spin Projected Unrestricted Moeller-Plesset L-form L-form bacteria L-form bacteria L-form bacteria L-fructose L-fructose L-fructose L-fucopyranose L-fucose L-galactomethylose L-GLRT l-gluonolactone oxidase

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The new drink, which contains citric acid, malic acid, L-cystine, phytic acid and methylsulfonylmethane (MSM), helps eliminate poisonous metals from the body while promoting adequate hydration.

Ako Kasei to Bring to Market New Functional Soft Drink for Metal ... by JCNN News Summaries

the new lychee-flavored beverage contains chelate compounds such as L-cystine, malic acid, methylsulfonylmethane and phytic acid, discharging poisonous metals from the body.

Akokasei to Market New Functional Beverage Toru-Tohru Water by JCNN News Summaries

Cystine (redirected from L-cystine)

Cystine
(redirected from L-cystine)