Azido-PEG4-Val-Cit-PAB-OH

• CAT Number: I016808
• CAS Number: 2055024-64-9
• Molecular Formula: C29H48N8O9
• Molecular Weight: 652.74
• Purity: ≥95%
• Synonyms: (2S)-2-[N-[(2S)-2-[3-[2-[2-[2-(2-azidoethoxy)ethoxy]ethoxy]ethoxy]propanoylamino]-3-methylbutanoyl]-4-(hydroxymethyl)anilino]-5-(carbamoylamino)pentanamide
• InChI: InChI=1S/C29H48N8O9/c1-21(2)26(35-25(39)9-12-43-14-16-45-18-19-46-17-15-44-13-11-34-36-32)28(41)37(23-7-5-22(20-38)6-8-23)24(27(30)40)4-3-10-33-29(31)42/h5-8,21,24,26,38H,3-4,9-20H2,1-2H3,(H2,30,40)(H,35,39)(H3,31,33,42)/t24-,26-/m0/s1
• InChIKey: YKWCEPIPEDFAAV-AHWVRZQESA-N
• SMILES: CC(C)C(C(=O)N(C1=CC=C(C=C1)CO)C(CCCNC(=O)N)C(=O)N)NC(=O)CCOCCOCCOCCOCCN=[N+]=[N-]

Azido-PEG4-Val-Cit-PAB-OH(CAT: I016808) is a cleavable, heterobifunctional linker widely used in antibody–drug conjugates (ADCs) and targeted drug delivery systems. It contains an azide group for copper-catalyzed azide–alkyne cycloaddition (“click chemistry”) and a Val-Cit-PAB sequence that is specifically cleaved by cathepsin B in lysosomes, ensuring selective intracellular drug release. The terminal hydroxyl group serves as a versatile handle for further derivatization, expanding customization options. The PEG4 spacer improves solubility, reduces steric hindrance, and enhances conjugation efficiency. Azido-PEG4-Val-Cit-PAB-OH is a powerful tool for constructing stable, cleavable linkers in chemical biology, ADC development, and precision therapeutic research.