Cystine is the oxidized derivative of the amino acid cysteine and has the formula (SCH 2 CH(NH 2)CO 2 H) 2. It is a white solid that is poorly soluble in water. As a residue in proteins, cystine serves two functions: a site of redox reactions and a mechanical linkage that allows proteins to retain their three-dimensional structure. [1]

半胱氨酸 （Cysteine，可簡寫為 Cys 或 C） [1] 是20種天然氨基酸之一，是一種含硫（與 甲硫氨酸 一樣）的非必需氨基酸。 動物 體內可經由 甲硫胺酸 和 絲氨酸 合成。 有缓解修复放射线对人体的损伤作用。 在人体内还有范围广泛的 解毒 作用，是 丙烯腈 及芳香族酸中毒的治疗用药。 半胱氨酸有助於戒除酒癮，為腦部及肝臟作用時所需；對肝臟細胞的新生而言是必需品。 半胱氨酸根據研究，可提升腎上腺素，可能引起某些人失眠。 Nagano N, Ota M, Nishikawa K. Strong …

Cysteine (/ ˈsɪstɪiːn /; [5] symbol Cys or C[6]) is a semiessential [7] proteinogenic amino acid with the formula HS−CH2−CH (NH2)−COOH. The thiol side chain in cysteine enables the formation of disulfide bonds, and often participates in enzymatic reactions as a nucleophile. Cysteine is chiral, but both D and L -cysteine are found in nature.

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, a crystalline, sulfur-containing amino acid that is formed from two molecules of the amino acid cysteine. Cystine can be converted to cysteine by reduction (in this case, the addition of hydrogen). Discovered in 1810, cystine was not recognized as a component of proteins until 1899, when it was isolated from animal horn.

胱氨酸（Cystine）协助皮肤的形成，且对解毒作用很重要，借由减低身体吸收铜的能力，胱氨酸保护细胞免于铜中毒。 当它被代谢时，会释放硫酸，而硫酸会与其他物质产生化学作用，增加整个代谢系统的解毒功能。

L-胱氨酸 （L-Cystine），是一种 有机物 ，分子式为C 6 H 12 N 2 O 4 S 2 ，分子量为240.3，白色六角形板状结晶或白色结晶粉末，溶于稀酸和碱溶液，极难溶于水，不溶于 乙醇 。

L-Cystine is an orally active extracellular form of L-Cysteine (HY-Y0337), occurring in proteins of plants and animals. L-Cystine elevates Nrf2 protein expression and activates Nrf2 transcription factor. L-cystine reduces ROS generation and protects against oxidant- or Doxorubicin (HY-15142A)-induced apoptosis.

胱氨酸 （Cystine），学名“二 (β-硫-α-氨基丙酸)”，是两分子 半胱氨酸 经 氧化 得到的 氨基酸，是一种 含硫氨基酸，属于 二硫化物 类。 无色或白色六角形板状晶体或结晶粉末，无味。 等电点 4.6。 L-型 （c = 1～2％，于5摩尔/升 盐酸 中）。 难溶于水，不溶于 乙醇 、 乙醚 、 苯 、 氯仿，易溶于稀酸、碱中。 有三种异构体： 左旋体 （L - (−)-胱氨酸）、右旋体（D - (+)-胱氨酸）、 内消旋体。 容易被 乙硫醇 、 二硫苏糖醇 等 还原剂 还原，还原后 二硫键 拆开成两个 半胱氨酸 …

Cystine is a type of amino acid that is formed by the oxidation of two molecules of cysteine, which are amino acids containing sulfur. It plays a crucial role in stabilizing the structure of proteins by forming disulfide bonds between cysteine residues. You might find these chapters and articles relevant to this topic.