Cysteine vs. Cystine

Cysteinenoun

(amino acid) A sulphur-containing nonessential amino acid C3H7NO2S found in most animal proteins; it readily oxidizes to cystine.

Cysteinenoun

an amino acid containing sulfur that is found in most proteins; oxidizes on exposure to air to form cystine

Cysteine

Cysteine (symbol Cys or C; ) is a semiessential proteinogenic amino acid with the formula HOOC-CH-(NH2)-CH2-SH. The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile. The thiol is susceptible to oxidation to give the disulfide derivative cystine, which serves an important structural role in many proteins.

Cystinenoun

(chemistry) A nonessential amino acid formed by the oxidation of cysteine; it contains two cysteine residues linked by a disulfide bond.

Cystinenoun

A white crystalline substance, C3H7NSO2, containing sulphur, occuring as a constituent of certain rare urinary calculi, and occasionally found as a sediment in urine.

Cystinenoun

a crystalline amino acid found in proteins (especially keratin); discovered in bladder stones

Cystine

Cystine is the oxidized dimer form of the amino acid cysteine and has the formula (SCH2CH(NH2)CO2H)2. It is a white solid that is slightly soluble in water.