[Inactivation of sodium dithionite reduced cytochromes P-450 of different origins].

The inactivation of five dithionite reduced soluble cytochrome P-450 isoforms has been studied. The inactivation of microsomal rabbit liver isoform LM2 and bacterial linalool cytochrome P-450 is followed by its conversion into cytochrome P-420. Microsomal rabbit liver isoform LM4, bacterial camphor and p-cymene cytochromes P-450 were not inactivated under these conditions.

[Cytochrome P-450 distribution in endoplasmic reticulum membranes of rat liver].

Using electron-dense labelling in combination with solubilization, the localization of cytochrome P-450 in the microsomal membranes was studied. It was shown that cytochrome P-450 is unevenly distributed in the membrane and has 2-3 reactive SH-groups. The molecules of solubilized cytochrome P-450 contain 4-5 reactive SH-groups and show a tendency to aggregate.

[Accessibility of microsomal membrane proteins for protease K].

The effect of protease K on the microsomal membrane proteins was studied. It was shown that treatment of the microsomal membranes by low concentrations of protease did not remove more than 35% of total membrane proteins. Treatment by higher protease concentrations removed about 50% of the proteins.