Triton promotes domain formation in lipid raft mixtures

被引:431
作者
Heerklotz, H [1 ]
机构
[1] Univ Basel, Biozentrum, CH-4056 Basel, Switzerland
关键词
D O I
10.1016/S0006-3495(02)75278-8
中图分类号
Q6 [生物物理学];
学科分类号
071011 ;
摘要
Biological membranes are supposed to contain functional domains (lipid rafts) made up in particular of sphingomyelin and cholesterol, glycolipids, and certain proteins. It is often assumed that the application of the detergent Triton at 4degreesC allows the isolation of these rafts as a detergent-resistant membrane fraction. The current study aims to clarify whether and how Triton changes the domain properties. To this end, temperature-dependent transitions in vesicles of an equimolar mixture of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, egg sphingomyelin, and cholesterol were monitored at different Triton concentrations by differential scanning calorimetry and pressure perturbation calorimetry. Transitions initiated by the addition of Triton to the lipid mixture were studied by isothermal titration calorimetry, and the structure was investigated by P-31-NMR. The results are discussed in terms of liquid-disordered (Id) and -ordered (to) bilayer and micellar (mic) phases, and the typical sequence encountered with increasing Triton content or decreasing temperature is Id, Id + Io, Id + Io + mic, and Io + mic. That means that addition of Triton may create ordered domains in a homogeneous fluid membrane, which are, in turn, Triton resistant upon subsequent membrane solubilization. Hence, detergent-resistant membranes should not be assumed to resemble biological rafts in size, structure, composition, or even existence. Functional rafts may not be steady phenomena; they might form, grow, cluster or break up, shrink, and vanish according to functional requirements, regulated by rather subtle changes in the activity of membrane disordering or ordering compounds.
引用
收藏
页码:2693 / 2701
页数:9
相关论文
共 45 条
[1]   On the origin of sphingolipid/cholesterol-rich detergent-insoluble cell membranes: Physiological concentrations of cholesterol and sphingolipid induce formation of a detergent-insoluble, liquid-ordered lipid phase in model membranes [J].
Ahmed, SN ;
Brown, DA ;
London, E .
BIOCHEMISTRY, 1997, 36 (36) :10944-10953
[2]   Condensed complexes and the calorimetry of cholesterol-phospholipid bilayers [J].
Anderson, TG ;
McConnell, HM .
BIOPHYSICAL JOURNAL, 2001, 81 (05) :2774-2785
[3]  
Blume A., 1988, PHYS PROPERTIES BIOL, P71, DOI [10.1007/978-1-4613-0935-2, DOI 10.1007/978-1-4613-0935-2]
[4]   Structure of detergent-resistant membrane domains: Does phase separation occur in biological membranes? [J].
Brown, DA ;
London, E .
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 1997, 240 (01) :1-7
[5]  
CHAPMAN D, 1974, J BIOL CHEM, V249, P2512
[6]  
Chellani Mohan, 1999, American Biotechnology Laboratory, V17, P18
[7]   Relationship of lipid rafts to transient confinement zones detected by single particle tracking [J].
Dietrich, C ;
Yang, B ;
Fujiwara, T ;
Kusumi, A ;
Jacobson, K .
BIOPHYSICAL JOURNAL, 2002, 82 (01) :274-284
[8]   Partitioning of Thy-1, GM1, and cross-linked phospholipid analogs into lipid rafts reconstituted in supported model membrane monolayers [J].
Dietrich, C ;
Volovyk, ZN ;
Levi, M ;
Thompson, NL ;
Jacobson, K .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2001, 98 (19) :10642-10647
[9]   Lipid rafts reconstituted in model membranes [J].
Dietrich, C ;
Bagatolli, LA ;
Volovyk, ZN ;
Thompson, NL ;
Levi, M ;
Jacobson, K ;
Gratton, E .
BIOPHYSICAL JOURNAL, 2001, 80 (03) :1417-1428
[10]   THERMAL-BEHAVIOR OF SYNTHETIC SPHINGOMYELIN-CHOLESTEROL DISPERSIONS [J].
ESTEP, TN ;
MOUNTCASTLE, DB ;
BARENHOLZ, Y ;
BILTONEN, RL ;
THOMPSON, TE .
BIOCHEMISTRY, 1979, 18 (10) :2112-2117