Definition of "cystine" []

• A white crystalline amino acid, C6H12N2O4S2, formed from the disulfide linkage of two cysteines during folding of many proteins, especially keratin, and stabilizing the tertiary structure of the protein. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "This occurs in cystine, which is known from the work of Count K.A.H. Mörner as a component of the protein molecule."
• "However, when it is present as a cysteine-cysteine dipeptide, called cystine, it is more stable than cysteine."
• "The four most common types of stones are comprised of calcium, uric acid, struvite, and cystine."