A disulfide bond joins two cysteine thiols by oxidation, linking two points of one chain (forming a ring) or two separate chains. Forming one removes two hydrogen atoms, so the oxidised peptide is 2.02 Da lighter than the reduced form.
When a peptide has more than two cysteines, the correct pairing must be controlled during synthesis. Disulfides can be broken by reducing agents, which is why buffers containing them are avoided when the ring must stay intact.
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For in vitro laboratory research only. Not for human or veterinary use. This library describes chemistry, analytical methods and published laboratory research; it gives no guidance on use in people or animals.