Endovesicle formation and membrane perturbation induced by polyoxyethyleneglycolalkylethers in human erythrocytes.
Polyoxyethyleneglycolalkylether (CmEn, m=12, n=8) can induce a large torocyte-like endovesicle in human erythrocytes. The present study aimed to examine how variations in the molecular structure of CmEn (m=10,12,14,16,18; n=1-10,23) affect the occurrence of torocyte endovesicles. Our results show that torocytes occur most frequently when m=12,14 and n=8,9. At this molecular configuration the detergents induce inward membrane bending (stomatocytic S1-S2 shapes) resulting in the formation of a large membrane invagination. These detergents have a strong membrane perturbing, i.e., haemolytic, effect. Theoretical calculations indicate that a torocyte-shaped inside-out membrane vesicle can be created from a large membrane invagination due to the impact of laterally mobile anisotropic membrane inclusions. Such inclusions may be detergent-membrane component complexes or unanchored integral membrane proteins. It is shown that a nonhomogeneous lateral distribution of anisotropic membrane inclusions may stabilise the torocyte endovesicle shape, characterised by having opposite membranes in the thin central region of the vesicles separated by a certain distance. Tubular, conical or inverted conical isotropic inclusions cannot do so.
Department of Biology, Abo Akademi University, Biocity, FIN-20520, Abo/Turku, Finland. henry.hagerstrand@abo.fi
Henry
H
Hägerstrand
Veronika
V
Kralj-Iglic
Miha
M
Fosnaric
Malgorzata
M
Bobrowska-Hägerstrand
Anna
A
Wróbel
Lucyna
L
Mrówczyńska
Thomas
T
Söderström
Ales
A
Iglic
D003902:Detergents / Q000494:pharmacology; D011992:Endosomes / Q000187:drug effects*; D004910:Erythrocyte Membrane / Q000187:drug effects*; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects / Q000648:ultrastructure*; D004987:Ethers / Q000494:pharmacology; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D010718:Phosphatidylserines; D011092:Polyethylene Glycols / Q000494:pharmacology
D003902:Detergents; D004987:Ethers; D010718:Phosphatidylserines; D011092:Polyethylene Glycols