N-(Mal-PEG2-carbonyl)-N-bis(PEG4-t-butyl ester) is a branched PEG linker possessing two t-butyl groups and a maleimide group; reactive toward thiol groups.
NHS ester-PEG4-Val-Cit-PAB-MMAE can be used in antibody drug conjugation. It has a PEG12 chain, a protease-sensitive Val-Cit dipeptide, a PAB linker and an MMAE payload.