Description

L-Cystine
Indications and Usage
Cystine is a dimeric amino acid formed by the oxidation of two cysteine residues which covalently link to make a disulfide bond. This organosulfur compound has the formula (SCH2CH(NH2)CO2H)2. It is a white solid, and melts at ******9 °C. It was discovered in ***0 by William Hyde Wollaston but was not recognized as being derived of proteins until it was isolated from the horn of a cow in ***9.[1] Through formation of disulfide bonds within and between protein molecules, cystine is a significant determinant of the tertiary structure of most proteins. Disulfide bonding, along with hydrogen bonding and hydrophobic interactions is partially responsible for the formation of the gluten matrix in bread. Human hair contains approximately 5% cystine by mass.
 
The disulfide link is readily reduced to give the corresponding thiol, cysteine. This reaction is typically effected with thiols such as mercaptoethanol or dithiothreitol.
(SCH2CH(NH2)CO2H)2   2 RSH → 2 HSCH2CH(NH2)CO2H   RSSR

For this reason, the nutritional benefits and sources of cystine are identical to those for the more common cysteine. Disulfide bonds cleave more rapidly at higher temperatures.
 
Package
*5kg/drum, double layers plastic bags inside.
 
Storage Situation
Stored in a cool and dry well-closed container. Keep away from moisture and strong light/heat.