CALORIMETRIC DETECTION OF CURVATURE STRAIN IN PHOSPHOLIPID-BILAYERS

被引:55
作者
EPAND, RM
EPAND, RF
机构
[1] Department of Biochemistry, McMaster University Health Sciences Centre, Hamilton, Ontario
关键词
D O I
10.1016/S0006-3495(94)80935-X
中图分类号
Q6 [生物物理学];
学科分类号
071011 ;
摘要
Phospholipids in biological membranes are arranged as bilayers. When constrained to pack into planar bilayers, certain phospholipids will form unstable structures as a consequence of their molecular shape and noncovalent bonding. This produces curvature strain which may provide energy for certain membrane processes. We demonstrate that an exothermic process associated with the relief of curvature strain can be detected calorimetrically. The enthalpy for the incorporation of a few percent lysophosphatidylcholine into large unilamellar vesicles of monomethyldioleoylphosphatidylethanolamine at pH 7.4 is exothermic but it is endothermic for stable bilayers such as this same lipid at pH 9 or dioleoylphosphatidylcholine at pH 7.4 or 9. The addition of lysophosphatidylcholine to monomethyldioleoylphosphatidylethanolamine at pH 7.4 is exothermic only for the addition of the first few percent of lysophosphatidylcholine and then it becomes endothermic. The size of the exothermic heat change is sensitive to changes in temperature, while the endothermic processes are relatively temperature-insensitive. The exothermic heat is also larger when 1 or 2 mol % of diolein is incorporated into vesicles of monomethyldioleoylphosphatidylethanolamine. These results are all consistent with the exothermic process corresponding to the relief of curvature strain in bilayers having a tendency to convert to the hexagonal phase. It provides a demonstration that considerable energy may be released upon the incorporation of certain molecules into membranes which have a low radius of spontaneous curvature.
引用
收藏
页码:1450 / 1456
页数:7
相关论文
共 26 条
  • [1] DETERMINATION OF BILAYER-MEMBRANE BENDING STIFFNESS BY TETHER FORMATION FROM GIANT, THIN-WALLED VESICLES
    BO, L
    WAUGH, RE
    [J]. BIOPHYSICAL JOURNAL, 1989, 55 (03) : 509 - 517
  • [2] LIPID POLYMORPHISM AND THE FUNCTIONAL ROLES OF LIPIDS IN BIOLOGICAL-MEMBRANES
    CULLIS, PR
    DEKRUIJFF, B
    [J]. BIOCHIMICA ET BIOPHYSICA ACTA, 1979, 559 (04) : 399 - 420
  • [3] MEMBRANE-FUSION AND INVERTED PHASES
    ELLENS, H
    SIEGEL, DP
    ALFORD, D
    YEAGLE, PL
    BONI, L
    LIS, LJ
    QUINN, PJ
    BENTZ, J
    [J]. BIOCHEMISTRY, 1989, 28 (09) : 3692 - 3703
  • [4] A CALORIMETRIC STUDY OF PEPTIDE-PHOSPHOLIPID INTERACTIONS - THE GLUCAGON-DIMYRISTOYLPHOSPHATIDYLCHOLINE COMPLEX
    EPAND, RM
    STURTEVANT, JM
    [J]. BIOCHEMISTRY, 1981, 20 (16) : 4603 - 4606
  • [5] EPAND RM, 1991, CELL AND MODEL MEMBRANE INTERACTIONS, P135
  • [6] LIPID HEADGROUP AND ACYL CHAIN COMPOSITION MODULATE THE MI-MII EQUILIBRIUM OF RHODOPSIN IN RECOMBINANT MEMBRANES
    GIBSON, NJ
    BROWN, MF
    [J]. BIOCHEMISTRY, 1993, 32 (09) : 2438 - 2454
  • [7] Ginsburg, 1966, METHOD ENZYMOL, V8, P115, DOI DOI 10.1016/0076-6879(66)08014-5
  • [8] Gruner S. M., 1992, STRUCTURE BIOL MEMBR, P211
  • [9] X-RAY-DIFFRACTION STUDY OF THE POLYMORPHIC BEHAVIOR OF N-METHYLATED DIOLEOYLPHOSPHATIDYLETHANOLAMINE
    GRUNER, SM
    TATE, MW
    KIRK, GL
    SO, PTC
    TURNER, DC
    KEANE, DT
    TILCOCK, CPS
    CULLIS, PR
    [J]. BIOCHEMISTRY, 1988, 27 (08) : 2853 - 2866
  • [10] IMPLICATIONS OF A NONLAMELLAR LIPID PHASE FOR THE TIGHT JUNCTION STABILITY .2. REVERSIBLE MODULATION OF TRANSEPITHELIAL RESISTANCE IN HIGH AND LOW RESISTANCE MDCK-CELLS BY BASIC-AMINO-ACIDS, CA-2+, PROTAMINE AND PROTONS
    HEIN, M
    MADEFESSEL, C
    HAAG, B
    TEICHMANN, K
    POST, A
    GALLA, HJ
    [J]. CHEMISTRY AND PHYSICS OF LIPIDS, 1992, 63 (03) : 223 - 233