Journal article
Analysis of Integral Membrane Protein Contributions to the Deformability and Stability of the Human Erythrocyte Membrane
The Journal of biological chemistry, Vol.276(50), pp.46968-46974
12/14/2001
DOI: 10.1074/jbc.M107855200
PMID: 11595743
Abstract
Three major hypotheses have been proposed to explain the role of membrane-spanning proteins in establishing/maintaining membrane stability. These hypotheses ascribe the essential contribution of integral membrane proteins to (i) their ability to anchor the membrane skeleton to the lipid bilayer, (ii) their capacity to bind and stabilize membrane lipids, and (iii) their ability to influence and regulate local membrane curvature. In an effort to test these hypotheses in greater detail, we have modified both the membrane skeletal and lipid binding interactions of band 3 (the major membrane-spanning and skeletal binding protein of the human erythrocyte membrane) and have examined the impact of these modifications on erythrocyte membrane morphology, deformability, and stability. The desired changes in membrane skeletal and protein-lipid interactions were induced by 1) reaction of the cells with 4,4′-diisothiocyanostilbene-2,2′-disulfonate (DIDS), an inhibitor of band 3-mediated anion transport that dissociates band 3 into dimers (increasing its surface area in contact with lipid) and severs band 3 linkages to the membrane skeleton; 2) a fragment of ankyrin that ruptures the same ankyrin-band 3 bridge to the membrane skeleton, but drives the band 3 subunit equilibrium toward the tetramer (i.e. decreasing the band 3 surface area in contact with lipid); and 3) an antibody to the ankyrin-binding site on band 3 that promotes the same changes in band 3 skeletal and lipid interactions as the ankyrin fragment. We observed that although DIDS induced echinocytic morphological changes in the treated erythrocytes, it had little impact on either membrane deformability or stability. In contrast, resealing of either the ankyrin fragment or anti-band 3 IgG into erythrocytes caused spontaneous membrane fragmentation and loss of deformability/stability. Because these and other new observations cannot all be reconciled with any single hypothesis on membrane stability, we suggest that more than one hypothesis may be operative and provide an explanation of how each might individually contribute to net membrane stability.
Details
- Title: Subtitle
- Analysis of Integral Membrane Protein Contributions to the Deformability and Stability of the Human Erythrocyte Membrane
- Creators
- Heidi M Van Dort - Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-1393David W Knowles - Life Sciences Division, Lawrence Berkeley Laboratories, University of California, Berkeley, California 94720Joel A Chasis - Life Sciences Division, Lawrence Berkeley Laboratories, University of California, Berkeley, California 94720Gloria Lee - Life Sciences Division, Lawrence Berkeley Laboratories, University of California, Berkeley, California 94720Narla Mohandas - Life Sciences Division, Lawrence Berkeley Laboratories, University of California, Berkeley, California 94720Philip S Low - Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-1393
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.276(50), pp.46968-46974
- DOI
- 10.1074/jbc.M107855200
- PMID
- 11595743
- NLM abbreviation
- J Biol Chem
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Publisher
- Elsevier Inc
- Language
- English
- Date published
- 12/14/2001
- Academic Unit
- Iowa Neuroscience Institute; Immunology; Internal Medicine
- Record Identifier
- 9984070108802771
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