AN IMMUNOLOGICAL ENQUIRY INTO THE IDENTITY OF ASSIMILATORY AND DISSIMILATORY NITRATE REDUCTASE FROM ESCHERICHIA COLI

Abstract

The properties of the respiratory (dissimilatory) form of nitrate reductase and the assimilatory form of the same enzyme from E. coli cells were investigated. It was shown that each enzyme form was attached to cellular "particulate" material. Although each enzyme is reported in the literature to differ in its electron donor requirements, no differential assay could be established.Immunochemical investigations showed that the specific antibody against the highly purified respiratory form of enzyme could cross react with the assimilatory enzyme. Induction studies indicated that the increase in activity of the assimilatory form of nitrate reductase paralleled the increase in antigenic activity. These similarities between the respiratory and assimilatory form of nitrate reductase would indicate that few, if any, differences exist between the two forms.