Acid-PEG3-mono-methyl ester is a PEG linker with a carboxylic acid and methyl ester group. Methyl ester can be hydrolyzed under strong basic condition. The carboxylic acid can react with primary amines in the presence of EDC and HATU to form stable amide bonds. The hydrophilic PEG linker increases the water solubility of the compound in aqueous media.
