Changes in the u.v.-visible absorption spectrum of cytochrome b5 which occur upon addition of dicetyl phosphate, dimyristoyl phosphatidic acid (DMPA), or mixed DMPA/dimyristoyl phosphatidylcholine vesicles are consistent with haem transfer from the cytochrome to the membrane via an intermediate haemoprotein species. The effects of vesicle charge and concentration on the kinetics of haem transfer are discussed.
