ɑ-Mercapto-ω-Boc Amino PEG

PEG crosslinkers with Boc (tert-butyloxycarbonyl)-protected amino groups on one chain end. The Boc protecting group is stable in a wide range of conditions (including highly basic environments) but may be easily removed by (strong) acids such as TFA or at low pH in water to release the primary amine. The amine functional group at one end of the PEG linker molecule allows for selective and covalent attachment to other molecules with complementary functional groups, such as carboxylic acids or activated esters, aldehydes and epoxides. The newly formed bonds are amides, imines or secondary amines. Applicable for reversible or permanent crosslinking with PEG. This linear PEG derivative has a sulfhydryl group (-SH) on one chain end. The free thiol groups react readily with maleimido or iodacetamido functionalities or transition metal surfaces like gold, silver etc. Reaction with other free thiols leads to S-S disulfide bonds which can be cleaved by reducing agents. PEG thiols may also be conjugated by thiol-ene chemistry.