| Abstract: | The purification procedures of both soluble and membrane-bound forms of dopamine-beta-hydroxylase have been developed. The membrane-bound form was solubilized by a detergent. Both preparations have been obtained in electrophoretically homogeneous form. The yield of soluble and membrane-bound enzyme forms by a described procedure was 22 mg and 15 mg, correspondingly, from 100 g of chromaffin granules paste. A comparative analysis of the main physico-chemical properties of the two enzyme forms has shown their identity. The effects of pH, ionic strength, oxidants and reducers on the EPR spectra of the two forms of dopamine-beta-hydroxylase have been investigated. A comparison of the EPR spectra of the two forms of the enzyme suggests that the copper environment of soluble and membrane-bound dopamine-beta-hydroxylases is practically identical. |
