Hägerstrand H, Kralj-Iglic V, Fosnaric M, Bobrowska-Hägerstrand M, Wróbel A, Mrówczyńska L, Söderström T, Iglic A. Endovesicle formation and membrane perturbation induced by polyoxyethyleneglycolalkylethers in human erythrocytes.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2004;
1665:191-200. [PMID:
15471585 DOI:
10.1016/j.bbamem.2004.08.010]
[Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2003] [Revised: 08/19/2004] [Accepted: 08/26/2004] [Indexed: 11/20/2022]
Abstract
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.
Collapse