Binding of iproniazid to the polymeric forms of iodide peroxidase

14C labelled iproniazid binds to iodide peroxidase more effectively in low ionic strength buffer than in high ionic strength buffer, suggesting preferential binding to the monomeric form of iodide peroxidase. During column chromatography, under conditions that separate iodide peroxidase into multiple forms, iproniazid is bound selectively to the monomeric form. Thus, this antithyroid agent appears to bind preferentially to the monomeric enzyme form, or possibly to cause dissociation of the polymeric to the monomeric form.