Morphological change of cell membrane by interaction with domain-swapped cytochrome c oligomers.
Monomeric cyt c has been reported to bind to the mitochondrial membrane by electrostatic and hydrophobic interactions with anionic phospholipids. We have previously shown that domain-swapped oligomeric cyt c retains the secondary structure of the monomer, and its surface possesses a larger area and more charges compared to the monomer. However, the effect of oligomerization of cyt c on cells has yet to be revealed. Herein, we investigated the interaction of oligomeric cyt c with anionic phospholipid-containing vesicles and the outer membrane of HeLa cells. Oligomeric cyt c interacted more strongly than monomeric cyt c with anionic phospholipid-containing vesicles and the outer membrane of HeLa cells. Oligomeric cyt c induced lateral phase separation of lipids in LUVs and GUVs, thereby leading to membrane disruption, whereas monomeric cyt c did not. Morphological changes in HeLa cells resulted from interaction with oligomeric cyt c, but little from interaction with the monomer. These results show that domain-swapped oligomeric proteins might exhibit properties different to those of monomer in cell systems.
Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0192 (Japan).
Sendy
S
Junedi
Kazuma
K
Yasuhara
Satoshi
S
Nagao
Jun-Ichi
J
Kikuchi
Shun
S
Hirota
D000818:Animals; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D048430:Cell Shape; D045304:Cytochromes c / Q000737:chemistry / Q000378:metabolism*; D006367:HeLa Cells; D006736:Horses; D006801:Humans; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary
D008051:Lipid Bilayers; D008081:Liposomes; D010743:Phospholipids; D045304:Cytochromes c
cytochromes; domain swapping; liposomes; membrane morphology; protein oligomers