Modification of the targeting presequence of the bovine cytochrome P-450scc precursor lifting tissue-specific restrictions on its mitochondrial import

It has been found that a recombinant cytochrome P-450scc precursor supplemented with an extra MRGSH 6GIR sequence at the NH 2-terminus (6His-pP450scc) is imported into isolated rat liver and heart mitochondria as well as into yeast mitochondria. The import is coupled with proteolytic processing of the precursor resulting in the mature size form of cytochrome P-450scc. Modification of the targeting presequence responsible for its increased positive charge is supposed to lift the previously suggested tissue-specific restrictions on the pP450scc import into mitochondria.