cysteic acid

{{chembox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 443681658

| Name = {{sm|l}}-Cysteic acid

| ImageFile = L-Cysteic acid.svg

| ImageSize = 150px

| ImageName = L-Cysteic acid

| ImageFile1 = L-Cysteic-acid-3D-balls.png

| ImageSize1 = 140px

| ImageName1 = Ball-and-stick model

| IUPACName = (R)-2-Amino-3-sulfopropanoic acid

| OtherNames = 3-Sulfo-{{sm|l}}-alanine

|Section1={{Chembox Identifiers

| InChI = 1/C3H7NO5S/c4-2(3(5)6)1-10(7,8)9/h2H,1,4H2,(H,5,6)(H,7,8,9)/t2-/m0/s1

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 13100-82-8

| CASNo_Comment = (D/L)

| CASNo1_Ref = {{cascite|correct|CAS}}

| CASNo1 = 35554-98-4

| CASNo1_Comment = (D)

| CASNo2_Ref = {{cascite|correct|CAS}}

| CASNo2 = 498-40-8

| CASNo2_Comment = (L)

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = A3OGP4C37W

| UNII_Comment = (D/L)

| UNII1_Ref = {{fdacite|correct|FDA}}

| UNII1 = YWB11Z1XEI

| UNII1_Comment = (D)

| UNII2_Ref = {{fdacite|correct|FDA}}

| UNII2 = M6W2DJ6N5K

| UNII2_Comment = (L)

| EC_number = 207-861-3

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 65718

| PubChem = 25701

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 17285

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C3H7NO5S/c4-2(3(5)6)1-10(7,8)9/h2H,1,4H2,(H,5,6)(H,7,8,9)/t2-/m0/s1

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = XVOYSCVBGLVSOL-REOHCLBHSA-N

| DrugBank_Ref = {{drugbankcite|correct|drugbank}}

| DrugBank = DB03661

| SMILES = C(C(C(=O)O)N)S(=O)(=O)O

| MeSHName = Cysteic+acid

}}

|Section2={{Chembox Properties

| Properties_ref = {{RubberBible62nd|page=C259}}.

| C=3|H=7|N=1|O=5|S=1

| Appearance = White crystals or powder

| Density =

| MeltingPt = Decomposes around 272 °C

| Solubility = Soluble

}}

}}

Cysteic acid also known as 3-sulfo-{{sm|l}}-alanine is the organic compound with the formula HO₃SCH₂CH(NH₂)CO₂H. It is often referred to as cysteate, which near neutral pH takes the form ⁻O₃SCH₂CH(NH₃⁺)CO₂⁻.

It is an amino acid generated by oxidation of cysteine, whereby a thiol group is fully oxidized to a sulfonic acid/sulfonate group. It is further metabolized via 3-sulfolactate, which converts to pyruvate and sulfite/bisulfite. The enzyme L-cysteate sulfo-lyase catalyzes this conversion. Cysteate is a biosynthetic precursor to taurine in microalgae.{{Cite journal |last=Tevatia |first=Rahul |last2=Allen |first2=James |last3=Rudrappa |first3=Deepak |last4=White |first4=Derrick |last5=Clemente |first5=Thomas E. |last6=Cerutti |first6=Heriberto |last7=Demirel |first7=Yaşar |last8=Blum |first8=Paul |date=2015-05-01 |title=The taurine biosynthetic pathway of microalgae |url=https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1167&context=plantscifacpub |journal=Algal Research |language=en |volume=9 |pages=21–26 |doi=10.1016/j.algal.2015.02.012 |issn=2211-9264|url-access=subscription }} By contrast, most taurine in animals is made from cysteine sulfinate.{{cite journal|title=Dissimilation of C3-Sulfonates|author1=Cook, Alasdair M. |author2=Denger, Karin |author3=Smits, Theo H. M. |journal=Archives of Microbiology|year=2006|volume=185|issue=2|pages=83–90|doi=10.1007/s00203-005-0069-1|pmid=16341843|s2cid=28030645|url=http://nbn-resolving.de/urn:nbn:de:bsz:352-opus-67394}}