Nomenclature
CAS number: 56-89-3
l-Cystine; [
R-(
R*,R*)]-3,3′-dithiobis[2-aminopropanoic
acid]; dicysteine; β,β′-dithiodialanine; α-diamino-β-dithiolactic acid; β,β′-diamino-β,β′-dicarboxydiethyl disulfide; bis(β-amino-β-carboxyethyl) disulfide; Gelucystine (Parke-Davis).
C
6H
12N
2O
4S
2; mol wt 240.30.
C 29.99%, H 5.03%, N 11.66%, O 26.63%, S 26.69%.
Description and references
Non-essential amino acid for human development.
Formed by the dimerization of two cysteines, q.v. through the sulfur. These disulfide bridges occur
both within and between polypeptides; often found in extracellular
proteins. First amino acid described in 1810 by Wollaston. Isoln
from horn hydrolysate: K. A. H. M"orner, Z.
Physiol. Chem. 28, 595 (1899). Early chemistry
and biochemistry: Amino Acids and Proteins, D. M. Greenberg,
Ed. (Charles C. Thomas, Springfield, IL, 1951) 950 pp. passim; J. P. Greenstein, M. Winitz, Chemistry
of the Amino Acids vols 1-3 (John Wiley and
Sons, Inc., New York, 1961) pp. 1879-1928, passim. Distribution
in protein: R. C. Fahey et al., J. Mol. Evol. 10, 155 (1977). Review of lysosomal
transport including pathophysiology: W. Gahl in Pathophysiol.
Lysosomal Transp., J. G. Thoene, Ed. (CRC Press, Boca Raton,
FL, 1992) pp 45-71. Review of thermodynamics and kinetics: T. R.
Ralph et al., J. Electroanal. Chem. 375, 1-15 (1994); of electrosynthesis: eidem, ibid. 17-27.
Properties
Hexagonal tablets from water, dec 260-261° (sealed
tube). [α]D20 -223.4° (1.0N HCl). pK1 1; pK2 2.1; pK3 8.02; pK4 8.71 at 35°. Soly in water (g/l) at 25°: 0.112; at 50°: 0.239;
at 75°: 0.523; at 100°: 1.142. Quite sol in aq solns below pH 2
or above pH 8. Soly curves: Sano, Biochem.
Z. 168, 14 (1926). Insol in alc. Absorption
spectrum: Marchlewski, Nowotonowna, Bull.
Soc. Chim. Fr. [4] 39, 163, 166
(1926).Derivative
d-Form.
Nomenclature
CAS number: 349-46-2
Properties
Crystals. [α]D20 +223° (1.0N HCl). Soly in water at 25°: 0.057 g/l.Derivative
dl-Form.
Nomenclature
CAS number: 923-32-0
Properties
Crystals. Soly in water at 25°: 0.057 g/l.Derivative
meso-Form.
Nomenclature
CAS number: 6020-39-9
Properties
Crystals. Soly in water: 0.056 g/l.