A major structural base of the T-E pharmaceuticals is the novel “multi-arm linkers” invented by Immunwork–the parent company of T-E Meds . A multi-arm linker has one core, which is composed of a short peptide of natural amino acids and PEGylated amino acids with different numbers of (usually 2 to 6) EG units, 2 or more linking arms, and one coupling arm. At the ends of the linking arms are functional groups (Y) for the linkage with targeting or effector elements. At the end of the coupling arm is another functional group (X) for the conjugation with a targeting or effector molecule (or moiety); X may be a functional group for click chemistry or an SH-reactive group, such as maleimide. The maleimide group is neighbored by a cluster of acidic amino acids, which potentiates the maleimide group as an electrophile in reacting with an SH group.
Here are some examples of multi-arm linker units.