Enzymatic activation and trapping of luminol-substituted peptides and proteins. A possible means of amplifying the cytotoxicity of anti-tumor antibodies.

Glutathione and glucose oxidase (EC 1.1.3.4) conjugates containing covalently bound luminol were prepared as prototypes for peptides and proteins with latent, enzyme-activatable chemical reactivity. In the presence of small quantities of activated horseradish peroxidase, conjugated luminol molecules were oxidized to unstable free radicals which reacted rapidly with soluble proteins and cells. These observations are of interest in regard to possible sequential localization reactions in which a few molecules of cell-bound antibody-horseradish peroxidase would be used to catalytically alter and trap many molecules of a second (luminol-substituted) enzyme, toxin, or hapten in the same area, as might be desirable in promoting selective cell destruction.