Cysteine is a naturally occurring hydrophilic ("water loving")
amino acid which has a sulfhydryl (
SH) group and is found in most
proteins. When it is exposed to air it
oxidizes to form
cystine, which is two cysteine molecules joined by a
disulfide bond. One molecule of
water (H
2O) is the byproduct from the creation of each molecule of cystine.
- Symbol: C or Cys
- Side chain type: hydrophilic
- Mass: 121.16
- Isoelectric point: 5.05
