Azobenzene-containing, peptidyl α-ketoesters as photobiological switches of α-chymotrypsin

Three photoswitchable, peptidomimetic inhibitors of oc-chymotrypsin have been synthesised. The compounds comprise an azobenzene, an alpha -ketoester and L-phenylalanine. The compounds were photoisomerised to give enriched states of the (E) and (Z) isomers and these states were assayed against alpha -chymotrypsin. The inhibitors were shown to be moderately active with switching ability of between two- and three-fold between the two isomer-enriched states. The behaviour of the inhibitors in solution was examined; specifically, their hydration and configurational stability. (C) 2000 Elsevier Science Ltd. All rights reserved.