Degradation of side-chains of N-(2-hydroxypropyl)methacrylamide copolymers by lysosomal thiol-proteinases

Abstract
N-(2-Hydroxypropyl)methacrylamide copolymers bearing oligopeptide side-chains terminating in p-nitroaniline (NAp) [.alpha. potential drug delivery system] were incubated with rat liver lysosomal enzymes in the presence of the thiol glutathione, and the rate of Nap release was measured. Twelve of the 16 side-chains investigated were hydrolyzed to release NAp and in all but 1 case degradation was partially or totally inhibited by leupeptin. The effect of substrate concentration on the degradation of the most readily cleaved side-chain, -Ala-Gly-Val-Phe-NAp, was measured.