Regulation of bound peroxidase by polyamines and guanidines in maize scutellum

Peroxidase bound to the membrane either ionically or covalently, but not the free enzyme, is inhibited by polyamines and activated by guanidines. The ionically bound peroxidase detached from the membrane by Ca²⁺, or the peroxidase present in the cytosolic fraction, can be associated with the membrane fraction from which the ionically bound enzyme is removed, by Ca²⁺. The reconstituted membrane fraction, either with the enzyme solubilized by Ca²⁺, or with the cytosolic enzyme, can again be modulated by these compounds by changing the affinity of the enzyme for its substrate.