THE INTERACTION OF HORSE HEART CYTOCHROME-C WITH PHOSPHOLIPID-BILAYERS - STRUCTURAL AND DYNAMIC EFFECTS

The interaction of cytochrome c with phospholipid bilayers is reviewed . Special emphasis is given to the structural and dynamic perturbation s induced, either in the membrane lipid component or protein itself, b y the lipid-protein interaction. The lipid-induced perturbations in th e structure of cytochrome c involve: i) conformational changes in and around the heme crevice, converting the heme iron to a high-spin state ; and ii) a destabilisation/loosening of the overall tertiary and seco ndary structure. This highly mobile, partially unfolded intermediate o f cytochrome c has a remarkable resemblance to partially folded membra ne-bound intermediates of the precursor protein. The functional implic ations of lipid-protein intermediates for (apo) cytochrome c in (prote in-translocation) electron-transfer are discussed.