查看“︁胱氨酸”︁的源代码

{{noteTA|G1=Chemistry}}
{{Chembox
| Name = <small>L</small>-胱氨酸
| ImageFileL1 = Cystine-skeletal.png
| ImageSizeL1 = 150px
| ImageFileR1 = Cystine-3D-balls.png
| ImageSizeR1 = 150px
| IUPACName = (2''R'',2'''R'')-3,3'-Dithiobis(2-aminopropanoic acid)
| OtherNames = 双硫丙氨酸、3,3'-二硫代二丙氨酸
| Section1 = {{Chembox Identifiers
| CASNo = 56-89-3
| CASNo_Ref = {{cascite|correct|CAS}}
|  PubChem  =  595
|  SMILES  = O=C(O)C(N)CSSCC(N)C(O)=O
  |  IUPHAR_ligand  =  5413
|  ChemSpiderID_Ref  = {{chemspidercite|correct|chemspider}}|  ChemSpiderID  =  575
|  UNII_Ref  = {{fdacite|correct|FDA}}|  UNII  =  48TCX9A1VT
|  KEGG_Ref  = {{keggcite|correct|kegg}}|  KEGG  =  C01420
|  InChI  =  1/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)
|  InChIKey  =  LEVWYRKDKASIDU-UHFFFAOYAA
|  ChEMBL_Ref  = {{ebicite|correct|EBI}}|  ChEMBL  =  366563
|  StdInChI_Ref  = {{stdinchicite|correct|chemspider}}|  StdInChI  =  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)
|  StdInChIKey_Ref  = {{stdinchicite|correct|chemspider}}|  StdInChIKey  =  LEVWYRKDKASIDU-UHFFFAOYSA-N
|  ChEBI_Ref  = {{ebicite|correct|EBI}}|  ChEBI  =  35492
}}
| Section2 = {{Chembox Properties
| C=6 | H=12 | N=2 | O=4 | S=2
| Appearance = 
| Density = 
| MeltingPt = 260–261℃ (分解)
| BoilingPt = 
| Solubility = 190 mg/l (20℃)}}
| Section3 = {{Chembox Hazards
| ExternalMSDS = [http://msds.chem.ox.ac.uk/CY/l-cystine.html MSDS]
| FlashPt = 
| Autoignition = }}
}}

'''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。
__NOTOC__

==性质==
无色或白色六角形板状晶体或结晶粉末，无味。[[等电点]]4.6。[[D/L标记|L-型]] <math>\rm \ [\alpha ]_D^{25} -\!232^o</math>（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]]（<small>L</small>-(−)-胱氨酸）、右旋体（<small>D</small>-(+)-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]]。加热也会使二硫键断裂。<ref>{{cite journal en
  | author = M.A. Aslaksena, O.H. Romarheima, T. Storebakkena and A. Skrede
  | title = Evaluation of content and digestibility of disulfide bonds and free thiols in unextruded and extruded diets containing fish meal and soybean protein sources
  | journal = Animal Feed Science and Technology
  | volume = 128
  | issue = 3-4
  | pages = 320–330
  | date = 28 June 2006
  | doi = 10.1016/j.anifeedsci.2005.11.008 }}</ref>

==历史==
1810年首先由[[威廉·海德·沃拉斯頓]]从[[膀胱结石]]中发现。1832年，[[贝采利乌斯]]将其命名为胱氨酸。广泛存在于[[头发]]、[[骨]]、[[角蛋白]]中。人髮中的含量约为5％（以质量计）。<ref>{{OrgSynth | author = Gortner, R. A.; W. F. Hoffman, W. F. | title = l-Cystine | collvol = 1 | collvolpages = 194 | year = 1941 | prep = CV1P0194}}</ref>

==制取==
通常从人髮水解液中提取、精制而得。也可由[[半胱氨酸]]在碱性水溶液中氧化而得。

==用途==
胱氨酸是[[蛋白质]]的基本组分。蛋白质中两个半胱氨酸残基之间形成的二硫键对维持蛋白质的结构具有重要作用。也用于医药、食品、化妆品等行业。

==参见==
* [[胱氨酸尿症]]
* [[半胱氨酸]]

== 参考资料 ==
{{reflist}}

[[Category:二硫化物]]
[[Category:含硫氨基酸]]
[[Category:非蛋白氨基酸]]