Cytochrome c induces lipid demixing in weakly charged phosphatidylcholine/phosphatidylglycerol model membranes as evidenced by resonance energy transfer.
Resonance energy transfer (RET) between anthrylvinyl-labeled phosphatidylcholine (AV-PC) or phosphatidylglycerol (AV-PG) as donors and the heme groups of cytochrome c (cyt c) as acceptors was examined in PC/PG model membranes containing 10, 20 or 40 mol% PG with an emphasis on evaluating lipid demixing caused by this protein. The differences between AV-PC and AV-PG RET profiles observed at PG content 10 mol% were attributed to cyt c ability to produce segregation of acidic lipids into lateral domains. The radius of lipid domains recovered using Monte-Carlo simulation approach was found not to exceed 4 nm pointing to the local character of cyt c-induced lipid demixing. Increase of the membrane PG content to 20 or 40 mol% resulted in domain dissipation as evidenced by the absence of any RET enhancement while recruiting AV-PG instead of AV-PC.
Gorbenko
Galyna P
GP
Department of Biological and Medical Physics, V.N. Karazin Kharkiv National University, 4 Svobody Sq., Kharkiv, 61077, Ukraine. galyna.p.gorbenko@univer.kharkov.ua
Trusova
Valeriya M
VM
Molotkovsky
Julian G
JG
Kinnunen
Paavo K J
PK