IMPORT OF A MODIFIED FORM OF THE BOVINE CYTOCHROME P450(SCC) PRECURSOR INTO MITOCHONDRIA ISOLATED FROM VARIOUS TISSUES AND ORGANISMS

An Escherichia coli strain was constructed providing hypersynthesis of a recombinant cytochrome P450(scc) precursor supplemented with an ext ra MetArgGlySerHis(6)GlyIleArg sequence at the NH2-terminus (6His-pP45 0(scc))(4). A procedure for isolation and purification of 6His-pP450(s cc) has been elaborated. It has been found that the recombinant precur sor is imported into isolated rat liver and heart mitochondria as well as into yeast mitochondria. The import is coupled with proteolytic pr ocessing of the precursor resulting in the mature size form of cytochr ome P450(scc). Modification of the targeting presequence responsible f or its increased positive charge is supposed to lift the previously su ggested tissue-specific restrictions on the pP450(scc) import into mit ochondria.