Mal-amido-PEG1-C2-NHS ester is a nonclaevable ADC linker containing a maleimide group and an NHS ester. The NHS ester can be used to label the primary amines (-NH2) of proteins, amine-modified oligonucleotides, and other amine-containing molecules[1][2]
[1]. Hansen AM, et al. Microwave-assisted solid-phase synthesis of antisense acpP peptide nucleic acid-peptide conjugates active against colistin- and tigecycline-resistant E. coli and K. pneumoniae. Eur J Med Chem. 2019 Apr 15;168:134-145. [2]. Zhang ge, et al. Preparation and application of FAPalpha activated polypeptide magnetic nanosphere compound used for diagnosis of tumors. CN105524141A