2,2′-bispyridyl disulfide rapidly induces intramolecular disulfide bonds in peptides

A linear peptide containing two reduced cysteine residues can be rapidly converted to its oxidized cyclic form containing an intramolecular disulfide bond by adding an excess of 2,2'-bispyridyl disulfide (2,2'-dipyridyl disulfide or 2,2'-dithiodipyridine) to conventional buffer solutions. The reactants and products are easily separated by reverse-phase chromatography. This reaction will find wide application in forming intramolecular disulfide bonds because of its selectivity for free sulfhydryl groups, quickness, safety, and applicability under acidic conditions. (C) 1999 Elsevier Science Inc. All rights reserved.