Disulfide bond

A disulfide bond (SS-bond), also called a disulfide bridge, is a strong covalent bond between two sulfhydryl groups. This bond is very important to the folding, structure, and function of proteins.

Related Topics:
Covalent bond - Sulfhydryl group - Protein

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When two amino acids covalently bond to each other through their side chains, they normally do so through a disulfide bond. The particular side chain involved is the sulfhydryl group (-SH). Oxidation of the thiol group yields a disulfide (S-S) bond. The presence of S-S then helps to maintain the tertiary structure of the protein. An amino acid that commonly forms S-S bonds in proteins in cysteine. When two cysteines are bonded by an S-S bond, the resulting molecule between the two protein chains is called cystine. The figure below shows the formation of a disulfide bond. The R on each side group represents the remainder of the amino acid.

Related Topics:
Amino acid - S - H - Oxidation - Tertiary structure - Cysteine - Cystine

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R R

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