“…Enzyme activationp roved to be highly sensitivet o sterich indrance:T he half-life associatedw ithe nzymatic activationb yp lasmind ropped from 42 to 4min whent he activationw as combinedw itht he cyclizationo fN , N ' -ethylenediamine.A ntibody3 8C2-mediateda ctivation by ar etroaldol retro-Michael reactionhas been implementedtoliberate drugs or 4-nitrophenol (entry2,T able 2). [42,45,[100][101][102][103] Penicillin Ga midase (PGA) andB ovine Serum Albumin( BSA) have beenu sedt oc leave the phenylacetamide moiety (entry3,T able2) [34,38,44,45,55,92,96,99,100,[104][105][106][107][108] and ac arbamate [109] (entry 4, Table2), andl iberatev ariouss ubstrates. b-Glucuronidase (b-GUS) [33,40,43] (entry 5, Table2)a nd b-Galactosidase [110][111][112] (entry 6, Table2)h aveb eens uccessfully implementedtospecifically deliver bioactive substrates in tumors and in bacteria.…”