• Highly reactive NHS ester (both ends) with primary amines
• Enables MS cleavage via collision-induced dissociation (CID)
• High-purity crystallization reagent for protein structure and interaction characterization
• Semi-permeable membrane, can be used for intracellular cross-linking
• Insoluble in water (dissolve in DMF or DMSO first)

DSSO (disuccinimide sulfoxide) and DSBU (disuccinimide di-sulfoxide) Butylurea) (or BuUrBU) is a MS-cleavable and semipermeable membrane cross-linker containing an amine-reactive N-hydroxyl group at each terminus of a 7-carbon spacer arm (DSSO) or an 11-carbon spacer arm (DSBU) Succinimide (NHS) ester. Both cross-linkers have similar reactivity with DSS but have cleavable functionality in the linker region that can be cleaved in the gas phase using collision-induced dissociation (CID) during tandem MS (MS/MS) fragmentation. MS cleavage of DSSO or DSBU generates diagnostic ion doublets during MS2, enabling the identification of cross-linked peptides from dead-end modifications. Subsequently, cross-linked peptide fragments were identified using MeroX or XlinkX software. For DSSO, the ability to cleave cross-linked peptides during MS/MS enables the use of MS3 acquisition methods to facilitate peptide sequencing via traditional database search engines.

Note: For high-resolution analysis of cross-linked peptides, the recommended LC column for use with the Nanospray Flex source is the Acclaim PepMap 100 C18 LC column (Cat. No. 164940 or 164568) . For the EASY-Spray ion source, the recommended LC column is the EASY-Spray C18 LC column (Cat. No. ES900 or ES904).