noun
- a nonessential amino acid containing sulfur, found in proteins and important for the formation of disulfide bonds
Usage: biochemistry; also spelled cystein in some contexts
Examples
- Cysteine is one of the 20 standard amino acids used by cells to synthesize proteins.
- The disulfide bond between two cysteine residues helps stabilize the three-dimensional structure of proteins.
- Hair and nails contain high levels of cysteine, which contributes to their strength.
- Cysteine can be synthesized by the body from the amino acid methionine.
- Foods rich in cysteine include garlic, onions, and poultry.