Molecular glues for manipulating enzymes: trypsin inhibition by benzamidine-conjugated molecular glues.

Water-soluble bioadhesive polymers bearing multiple guanidinium ion (Gu) pendants at their side-chain termini (Glue -BA, = 10 and 29) that were conjugated with benzamidine (BA) as a trypsin inhibitor were developed. The Glue -BA molecules are supposed to adhere to oxyanionic regions of the trypsin surface, even in buffer, a multivalent Gu/oxyanion salt-bridge interaction, such that their BA group properly blocks the substrate-binding site. In fact, Glue-BA and Glue-BA exhibited 35- and 200-fold higher affinities for trypsin, respectively, than a BA derivative without the glue moiety (TEG-BA). Most importantly, Glue-BA inhibited the protease activity of trypsin 13-fold more than TEG-BA. In sharp contrast, Glue-BA, which bears 27 Gu units along the main chain and has a 5-fold higher affinity than TEG-BA for trypsin, was inferior even to TEG-BA for trypsin inhibition.