[Relation between the membrane and soluble forms of dopamine beta-monooxygenase].

The quantitative ratio of membrane-bound and soluble forms of dopamine beta-monooxygenase from chromaffin granules obtained under different experimental conditions was determined. The amount of the membrane-bound form of dopamine beta-monooxygenase made up to no less than 60% of the total enzyme pool, when the granules were obtained and lyzed in the presence of pepstatin, phenylmethylsulfonyl fluoride, N-ethylmaleimide and catalase. In the absence of protectors practically all the enzyme can be obtained in the soluble form without detergent treatment.

[Peptidylglycine alpha-amidating monooxygenase from bovine heart atrium secretory granules and adrenal chromaffin granules].

About 40-60% of the peptidylglycine alpha-amidating amonooxygenase activity in the lysates of secretory granules from bovine atria and adrenal medulla isolated and lyzed in the presence of pepstatin, phenylmethylsulfonyl gluoride, N-ethylmaleimide and catalase, was found to be in the soluble form. The remaining part bound to the membrane fraction was extracted with Triton X-100. The procedure of purification of the soluble form of peptidylglycine alpha-amidating monooxygenase from both atrial and chromaffin granules in electrophoretically homogeneous enzyme preparations was developed.

[Effect of hydrazine derivatives, plant growth regulators, on the cytochrome oxidase reaction].

Gidrel, digidrel, and sodium salt of maleic hydrazide were shown to exert no influence on oxygen consumption by cytochrome oxidase in concentrations up to 10(-1) M. Similar concentrations of N,N-dimethylamino-succinic acid hydrazide inhibited cytochrome oxidase but did not influence the optical spectrum of cytochrome oxidase.

The reactivation of apodopamine beta-monooxygenase by vanadyl ions.

Vanadyl ions may be used for reactivation of apodopamine beta-monooxygenase. Maximal activity of the enzyme was achieved at a 350-400-fold molar excess of vanadyl ions, whereas for maximal reconstitution with copper, an 8-10-fold molar excess of copper was necessary. AT higher concentrations of vanadyl as well as of copper, inhibition was observed.