THE COMPARATIVE-STUDY OF PEROXIDASE-ACTIVITY AND SUBSTRATE-BINDING PROPERTIES OF CYTOCHROME-P450 2B4 INCORPORATED INTO PHOSPHOLIPID-VESICLES WITH THE USE OF 2 DIFFERENT METHODS

The comparative study of peroxidase activities and substrate binding p roperties of cytochrome P450 2B4 in reconstituted vesicles prepared wi th the use of two different techniques, and microsomal cytochrome P450 was carried out. The data obtained show that the two types of cytochr ome P450 2B4-containing proteoliposomes do not differ substantially fr om each other with respect to H2O2- or cumene hydroperoxide-dependent substrate hydroxylation activities as well as substrate binding proper ties of hemoprotein reconstituted. However, some parameters measured w ith proteoliposomal cytochrome P450 are markedly different from those measured with microsomal hemoprotein, suggesting the existence of conf ormational differences between the molecules of these two cytochromes or the differences in the depth of their immersion into lipid bilayer.