DTSSP is 3,3′-Dithiobis(sulfosuccinimidylpropionate), which contains an amine-reactive N-hydroxysulfosuccinimide (sulfo-NHS) ester at each end of an 8-carbon spacer arm. Sulfo-NHS esters react with primary amines at pH 7-9 to form stable amide bonds, along with release of the N-hydroxysulfosuccinimide leaving group. Proteins, including antibodies, generally have several primary amines in the side chain of lysine (K) residues and the N-terminus of each polypeptide that are available as targets for sulfo-NHS-ester crosslinking reagents. DSS, the non-sulfonated analog of DTSSP is also available for applications that require a membrane-permeable crosslinker.
