m-PEG4-CH2COOH is a PEG linker containing a terminal carboxylic acid. The terminal carboxylic acid can react with primary amine groups in the presence of activators (e.g. EDC, or HATU) to form a stable amide bond. The hydrophilic PEG spacer increases solubility in aqueous media.
3,6,9,12-Tetraoxatridecanoic acid is a useful research chemical.
mPEG3-CH2COOH can be used to synthesise lipid couplers of oligo-(14-amino-3,6,9,12-tetraoxotetracosanoic acid) (ATTAn) as monodisperse analogues of poly(ethylene glycol) (PEG) derivatives for use in liposomal drug delivery systems[1]. mPEG3-CH2COOH contains terminal carboxylic acids. The terminal carboxylic acid readily reacts with primary and secondary amines under EDC, DCC, HATU or other amide coupling conditions to form stable amide bonds. mPEG modification increases the water solubility of the resulting compounds.
[1] STEVEN M. ANSELL. Application of Oligo-(14-amino-3,6,9,12-tetraoxatetradecanoic acid) Lipid Conjugates as Steric Barrier Molecules in Liposomal Formulations[J]. Bioconjugate Chemistry Bioconjugate, 1999. DOI:10.1021/bc990005p.