SPDP-C6-NHS ester

• CAT Number: R000705
• CAS Number: 158913-22-5
• Molecular Formula: C18H23N3O5S2
• Molecular Weight: 425.52
• Purity: ≥95%
• Synonyms: (2,5-dioxopyrrolidin-1-yl) 6-[3-(pyridin-2-yldisulfanyl)propanoylamino]hexanoate
• InChI: InChI=1S/C18H23N3O5S2/c22-14(10-13-27-28-15-6-3-5-12-20-15)19-11-4-1-2-7-18(25)26-21-16(23)8-9-17(21)24/h3,5-6,12H,1-2,4,7-11,13H2,(H,19,22)
• InChIKey: QYEAAMBIUQLHFQ-UHFFFAOYSA-N
• SMILES: C1CC(=O)N(C1=O)OC(=O)CCCCCNC(=O)CCSSC2=CC=CC=N2

SPDP-C6-NHS ester(CAT: R000705) (N-Succinimidyl 3-(2-pyridyldithio)propionate with a C6 spacer) is a heterobifunctional, cleavable crosslinker widely used in bioconjugation. It features an NHS ester group that reacts efficiently with primary amines on proteins, peptides, or other biomolecules to form stable amide bonds. The pyridyldithiol moiety enables thiol-specific coupling via disulfide exchange, allowing reversible linkage to cysteine residues or other sulfhydryl groups. The C6 alkyl spacer increases flexibility and reduces steric hindrance, improving conjugation efficiency in complex systems. This reagent is particularly valuable for preparing antibody–drug conjugates, protein–protein crosslinks, and cleavable probes where controlled, disulfide-based release is required.