601
|
|
602
|
|
603
|
Möhwald H. Thin Liquid Films. Edited byI. B. Ivanov. Marcel Dekker Inc, New York 1988. 1160 pp., bound, US $ 295.—ISBN 0-8247-7763-8. Angew Chem Int Ed Engl 1989. [DOI: 10.1002/ange.19891010455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
604
|
Abstract
Fluorescence micrographs of monolayers of L-alpha-dipalmitoylphosphatidylcholine (DPPC) at the air water interface are analyzed. Ordered phase domains in coexistence with the fluid lipid phase change their shapes with time and with lateral pressure. With domains fixed under an electrode and well separated from their neighbours a peculiar instability of the boundary lines is observed. It is ascribed to the onset of an electrostatically induced shape transition. Elaborating the boundary regions where domain fusion and fission, respectively, are observed leads to a model on in-plane dipole orientation.
Collapse
|
605
|
Kirstein S, Möhwald H, Shimomura M. Crystalline two-dimensional domains of cyanine dyes at interfaces. Chem Phys Lett 1989. [DOI: 10.1016/0009-2614(89)85360-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
606
|
Lösche M, Duwe HP, Möhwald H. Quantitative analysis of surface textures in phospholipid monolayer phase transitions. J Colloid Interface Sci 1988. [DOI: 10.1016/0021-9797(88)90142-7] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
607
|
|
608
|
Hörber J, Lang C, Hänsch T, Heckl W, Möhwald H. Scanning tunneling microscopy of lipid films and embedded biomolecules. Chem Phys Lett 1988. [DOI: 10.1016/0009-2614(88)80169-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
609
|
Barraud A, Flörsheimer M, Möhwald H, Richard J, Ruaudel-Teixier A, Vandevyver M. Morphology and crystalline nature of a Langmuir—Blodgett film of a TCNQ charge transfer salt. J Colloid Interface Sci 1988. [DOI: 10.1016/0021-9797(88)90451-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
610
|
Heckl WM, Zaba BN, Möhwald H. Interactions of cytochromes b5 and c with phospholipid monolayers. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 903:166-76. [PMID: 2820486 DOI: 10.1016/0005-2736(87)90166-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Monolayers of charged and neutral phospholipids at the air/water interface containing the cytochromes b5 and c are studied by film balance techniques and by fluorescence microscopy. A new technique is introduced to obtain a defined and homogeneous protein distribution within the membrane. It is shown that both proteins preferentially partition into the fluid membrane phases coexisting with solid lipid domains, thus allowing formation of periodic protein distributions. Protein reconstitution in protein/lipid ratios up to 1:50 does not change the pressure, pi c, corresponding to the main lipid transition but changes the slope in the pressure/area isotherms. It also affects the pressure-induced lipid crystallization, in that the monolayer can be viewed as segregated into a protein-free and a protein-enriched phase. Whereas penetration of cytochrome c into the monolayer is highly dependent on lipid head group charge, this does not hold for cytochrome b. In both cases, monolayer penetration is monotonously reduced with increasing surface pressure, pointing to the dependence of hydrophobic protein-lipid interactions on hydrocarbon chain density.
Collapse
|
611
|
Abstract
Monolayers of the phospholipid dimyristoyl phosphatidic acid on the surface of water have been studied by a combination of the new techniques of synchrotron x-ray diffraction and fluorescence microscopy with classical surface pressure data. The pressure vs. area isotherm changes slope at the surface pressures pi c and pi s. The optical technique demonstrates that between pi c and pi s the fluid phase coexists with a denser "gel" phase. Electron diffraction data have shown that the gel phase has bond orientational order over tens of micrometers. However, the x-ray data demonstrate that positional correlations extend only over tens of angstroms. Thus, the gel phase is not crystalline. Above pi s a solid phase is formed with a positional correlation range that is eight times longer for the chemically purest films.
Collapse
|
612
|
Kjaer K, Als-Nielsen J, Helm CA, Laxhuber LA, Möhwald H. Ordering in lipid monolayers studied by synchrotron x-ray diffraction and fluorescence microscopy. PHYSICAL REVIEW LETTERS 1987; 58:2224-2227. [PMID: 10034685 DOI: 10.1103/physrevlett.58.2224] [Citation(s) in RCA: 229] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
613
|
Miller A, Möhwald H. Diffusion limited growth of crystalline domains in phospholipid monolayers. J Chem Phys 1987. [DOI: 10.1063/1.451886] [Citation(s) in RCA: 107] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
614
|
|
615
|
Heckl WM, Lösche M, Cadenhead DA, Möhwald H. Electrostatically induced growth of spiral lipid domains in the presence of cholesterol. EUROPEAN BIOPHYSICS JOURNAL : EBJ 1986; 14:11-7. [PMID: 3816696 DOI: 10.1007/bf00260398] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The formation of crystalline domains of the phospholipid L-alpha-dimyristoyl-phosphatidic acid containing 1 mol% cholesterol, was studied as a function of head group charge by fluorescence microscopy with monolayers at the air/water interface. It is shown that the usual dendritic growth occurs at low pH (8), whereas spiral domains are formed at high pH (11), where the head group contains two negative charges. The findings are ascribed to an electrostatically induced chain tilt that, in conjunction with an in-plane dipole moment, causes a ferroelectric state. This allows for domain aggregation and orientation originating in elongated domains that, additionally, are bent because of the chirality of the molecules. The structure is stabilized and further elongated due to the anisotropic edge activity of cholesterol.
Collapse
|
616
|
Miller A, Knoll W, Möhwald H. Fractal growth of crystalline phospholipid domains in monomolecular layers. PHYSICAL REVIEW LETTERS 1986; 56:2633-2636. [PMID: 10033049 DOI: 10.1103/physrevlett.56.2633] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
617
|
Laxhuber L, Scheunemann U, Möhwald H. Photothermal reaction kinetics and thermal desorption of diacetylene langmuir-blodgett films. Chem Phys Lett 1986. [DOI: 10.1016/0009-2614(86)85076-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
618
|
Bozsik M, Helm C, Laxhuber L, Möhwald H. Vanadyl binding to phospholipid membranes. J Colloid Interface Sci 1985. [DOI: 10.1016/0021-9797(85)90204-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
619
|
Heckl WM, Lösche M, Scheer H, Möhwald H. Protein/lipid interactions in phospholipid monolayers containing the bacterial antenna protein B800–850. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1985. [DOI: 10.1016/0005-2728(85)90207-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
620
|
Riegler J, Peschke J, Möhwald H. Two-dimensional electron transfer from cytochrome C to photosynthetic reaction centers. Biochem Biophys Res Commun 1984; 125:592-9. [PMID: 6097243 DOI: 10.1016/0006-291x(84)90580-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The arrangement and the electron transfer are studied for photosynthetic reaction centers (RC) of Rhodopseudomonas sphaeroides reconstituted into phospholipid vesicles. Freeze-etch electron micrographs of phase separated mixed vesicles reveal an RC enrichment in the phase containing the acidic lipid serine. It is demonstrated that the electron transfer from cytochrome c to RC involves a two-dimensional diffusion of the membrane bound electron donor with diffusion coefficients (D approximately 10(-9) cm2/sec) characteristic for membrane proteins.
Collapse
|
621
|
Lösche M, Möhwald H. Impurity controlled phase transitions of phospholipid monolayers. EUROPEAN BIOPHYSICS JOURNAL : EBJ 1984; 11:35-42. [PMID: 6468343 DOI: 10.1007/bf00253856] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The phase diagram of monolayers of L-alpha-dimyristoyl phosphatidic acid has been studied by fluorescence microscopy. For pressures corresponding to the nearly horizontal slope in the pressure area diagram the growth of crystalline platelets can be observed. They are of dendritic nature; their sizes can be controlled via pressure, compression speed, temperature and pH, and increased up to 100 micron. Due to repulsive interaction a hexagonal arrangement of crystalline platelets can be established. It is shown that the textures do not depend on the dye probe for concentrations below 3 mol%. On the other hand via incorporation of impurities in concentrations of about 1 mol% the coexistence of lipid and solid phases can be controlled. Since, for a constant surface pressure, this coexistence can be maintained, these monolayers are suitable model systems to study the interactions of proteins and vesicles with coexisting fluid and solid membrane areas.
Collapse
|
622
|
Fischer A, Lösche M, Möhwald H, Sackmann E. On the nature of the lipid monolayer phase transition. ACTA ACUST UNITED AC 1984. [DOI: 10.1051/jphyslet:019840045016078500] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
623
|
Laxhuber L, Möhwald H, Hashmi M. Secondary-ion mass spectrometry of organized organic model systems. ACTA ACUST UNITED AC 1983. [DOI: 10.1016/0020-7381(83)85031-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
624
|
Luisetti J, Möhwald H, Galla HJ. Spectroscopic and Thermodynamic Studies of Chlorophyll Containing Monolayers and Vesicles. ACTA ACUST UNITED AC 1979. [DOI: 10.1515/znc-1979-5-615] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract Absorption and fluorescence experiments on pheophytin and chlorophyll containing lipid bilayer vesicles are reported. Pheophytin aggregates on the vesicles are established from an additional red shifted band (at 695 nm) in the absorption spectrum. These aggregates contain pheophytin in an arrangement with the molecular planes of the porphyrin rings being parallel and cover about 10% of the vesicle surface. The lipid phase dissolves pheophytin up to a molar ratio of 15% above the lipid phase transition. This solubility limit decreases hardly on solidification of the lipid.For chlorophyll a containing vesicles the aggregates are not observed in the absorption spectrum. The chlorophyll solubility is about equal to that of pheophytin. This suggests that the phase separa tion indicated from fluorescence measurements at temperatures below the lipid phase transition does not lead to the formation of strongly bound chlorophyll aggregates.
Collapse
|
625
|
Luisetti J, Möhwald H, Galla HJ. Monitoring the location profile of fluorophores in phosphatidylcholine bilayers by the use or paramagnetic quenching. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 552:519-30. [PMID: 221020 DOI: 10.1016/0005-2736(79)90196-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Spin probes differing in the position of their paramagnetic centre are used to quench the fluorescence of pyrene derivatives and chlorophylls incorporated into dimyristoyl phosphatidylcholine membranes. Pyrene butyric acid and pyrene decanoic acid with known orientation relative to the membrane surface are investigated. The quenching efficiency of fatty acid spin probes is dependent on the position of the nitroxide radical group in the fatty acid chain. Using this short range interaction we developed a spectroscopic method to chlorophyll-containing vesicles, we were able to characterize the orientation of the porphyrin ring within the membrane. Moreover, the chlorophyll fluorescence is also quenched by a water-soluble spin label. Therefore the porphyrin ring appears to be orientated in the polar head group region of the lipid layer, but not to be protruding out into the water phase. This conclusion is confirmed by the use of pyrene derivatives. Fluorescence quenching by a water-soluble spin label within the lipid matrix is observed even in the rigid state of the membrane. Fluorescence lifetime measurements suggest the existence of two different quenching mechanisms: (1) a static quenching occurring below the lipid phase transition temperature, and (2) an additional dynamic quenching taking place in the fluid state of the lipid bilayer.
Collapse
|