Chimeric molecules employing horseradish peroxidase as reporter enzyme for protein localization in the electron microscope.

摘要: Publisher Summary This chapter discusses the chimeric molecules employing horseradish peroxidase as reporter enzyme for protein localization in electron microscope. Peroxidase is detectable microscope because presence of hydrogen peroxide it reacts enzymatically with diaminobenzidine (DAB) to form an insoluble, electron-opaque product. Its enzymatic activity provides amplification step that makes (HRP) extremely sensitive tracer. An estimate using liposomes suggested a single HRP molecule enveloped within 50-nm-diameter vesicle sufficient fill lumen DAB reaction product believed be complex, cross-linked mixture tarlike substances, which during its formation cross-links other macromolecules located immediate vicinity. Endogenous present peroxisomes and compartments, such leukocyte granules, contain myeloperoxidase. Inhibitors can selectively block this living cells are available, but they have not been widely used localizations endogenous peroxidases readily demonstrable, complicating factor most tracer studies.