Bis-PEG8-acid is a PEG linker containing terminal carboxylic acid groups. The hydrophilic PEG spacer increases solubility in aqueous media. The terminal carboxylic acids can react with primary amine groups in the presence of activators (e.g. EDC, or HATU) to form a stable amide bond.
Bis-PEG8-acid is a PEG-based PROTAC linker can be used in the synthesis of PROTACs. Bis-PEG8-acid is a cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADCs)[1].
[1] Gregory Slobodkin, et al. Polyamine derivatives. WO2010108108A2