Phase transitions in phospholipid bilayers: Lateral phase separations play vital roles in biomembranes

Eze, Michael O.

doi:10.1016/0307-4412(91)90103-f

Cited by 41 publications

(36 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lipid bilayers have been extensively investigated using various http techniques [5,6]. We know that the phase in which we find supported phospholipid bilayers depends on many factors among them type of lipid and temperature are important ones [7,8]. For freely floating fully hydrated DPPC four distinct phases -subgel (L 0 c ), gel (L 0 b ), ripple (P 0 b ) and fluid (L a ) -have been described [9].…”

Section: Introductionmentioning

confidence: 99%

The effect of temperature on supported dipalmitoylphosphatidylcholine (DPPC) bilayers: Structure and lubrication performance

Wang

Zander²,

Liu

et al. 2015

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

Phospholipids fulfill an important role in joint lubrication. They, together with hyaluronan and glycoproteins, are the biolubricants that sustain low friction between cartilage surfaces bathed in synovial fluid. In this work we have investigated how the friction force and load bearing capacity of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayers on silica surfaces are affected by temperature, covering the temperature range 25-52°C. Friction forces have been determined utilizing the AFM colloidal probe technique, which showed that DPPC bilayers are able to provide low friction forces over the whole temperature interval. However, the load bearing capacity is improved at higher temperatures. We interpret this finding as being a consequence of lower rigidity and higher self-healing capacity of the DPPC bilayer in the liquid disordered state compared to the gel state. The corresponding structure of solid supported DPPC bilayers at the silica-liquid interface has been followed using X-ray reflectivity measurements, which suggests that the DPPC bilayer is in the gel phase at 25°C and 39°C and in the liquid disordered state at 55°C. Well-defined bilayer structures were observed for both phases. The deposited DPPC bilayers were also imaged using AFM PeakForce Tapping mode, and these measurements indicated a less homogeneous layer at temperatures below 37°C.

show abstract

Section: Introductionmentioning

confidence: 99%

The effect of temperature on supported dipalmitoylphosphatidylcholine (DPPC) bilayers: Structure and lubrication performance

Wang

Zander²,

Liu

et al. 2015

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

show abstract

“…This is because of the presence of unsaturated bonds, which disrupt the ordered array of hydrocarbon chains. Consequently, the liquid crystalline layer is less packed and more permeable (Eze 1991). The occurrence of phospholipids in different phases at the measurement temperature causes phase separation in the mixture, which is proved by the positive values of the excess free enthalpy of mixing (see the "Analysis of Langmuir Monolayers" section).…”

Section: Contact Angles Analysismentioning

confidence: 99%

“…In fact, the formation of lipid domains is a key process by which biomembranes perform various functions (Eze 1991;Simons and Ikonen 1997;Welti and Glaser 1994), including mechanisms of recognition, signalling, active transport, endocytosis or exocytosis, microbial growth and homeoviscous (or homeophasic) adaptation to various environments (Eze 1990(Eze , 1991McElhaney 1984). The membrane acquires heterogeneity in both the polar head group and the acyl chain compositions to maintain the fluidity and physical state at any particular instance (Eze 1990(Eze , 1991McElhaney 1984). Therefore, in membrane research, controlling the lipid composition is necessary to understand the relationship between the lipid domains and the functional properties of membrane.…”

Section: Introductionmentioning

confidence: 99%

Wettability of Binary Solid-Supported Films of Zwitterionic/Anionic Phospholipids

Jurak

2015

Adsorption Science & Technology

View full text Add to dashboard Cite

ABSTRACT:The effect of different amounts of anionic phosphatidylglycerol in the zwitterionic phosphatidylcholine monolayers on their properties was quantitatively described in terms of the interactions between these two compounds as well as the changes of mixed monolayers' apparent surface free energy and its components. For all Langmuir films, surface pressure-area per molecule (π-A) isotherms were used to monitor the surface thermodynamics (i.e. the excess area and excess free enthalpy of mixing). This allowed to evaluate the kind and magnitude of interactions that have an influence on the phase behaviour and structural properties of the monolayers. Then, assuming that the molecular properties of Langmuir films are preserved upon transfer to a solid support, further characterizations were accomplished with advancing and receding contact angle measurements on the Langmuir-Blodgett films deposited at 35 mN/m on mica. These enabled the possibility to track changes in the wettability of the tightly packed or phase-separated phospholipid films and their surface free energy as a function of the monolayer composition. It is believed that these results throw a light on better understanding of the organizational structure of lipid films and their interactions with the surrounding environment. Moreover, the obtained results can be also helpful to identify the optimal lipid composition in the production of more effective therapeutic surfactants.

show abstract

“…Of the four major biomolecules-proteins, nucleotides, sugars, and lipids-lipids are by far the least frequently encountered in the undergraduate laboratory. For example, in the last 40 years, only eight papers (e.g., [1][2][3][4]) concerning lipids and membranes were published in this journal, five of which described undergraduate laboratory projects. Over this same time period, eight more lipid/membrane papers (e.g., [5][6][7][8][9][10]) were published in the Journal of Chemical Education, six of which presented laboratory projects.…”

Section: Introductionmentioning

confidence: 99%

“…Physical characteristics of the membrane bilayer are controlled by the lipid composition of the membrane [4,6], including fatty acid length and unsaturation, and head group size and charge [10,12,14]. Three main physical characteristics of the bilayer influence biological function: fluidity [3,4,7,10,15,16], permeability [3,5,8,9,17], and protein interaction [2,10,16,18]. Fluidity is a key parameter, directly altering membrane permeability [16], and indirectly influencing protein interactions [2,10,16,18].…”

Section: Introductionmentioning

confidence: 99%

Liposome permeability probed by laser light scattering

Silverstein

Williamson

2019

Biochem Molecular Bio Educ

View full text Add to dashboard Cite

We have developed a laboratory project in which students prepare liposomes, expose them to hyperosmotic and hypoosmotic solutions, and follow the resulting shrinking and swelling (respectively) with laser light scattering. Each light intensity transient can be fit to an exponential decline or rise, with the decay constant (k) and the amplitude (ΔVmax) being indirectly related to the kinetics and thermodynamics (respectively) of transmembrane osmotic flux. Students vary the experimental system by changing the types and concentrations of osmolytes such as alcohols, amides, and salts. Students then compare how these changes alter the rate and extent of osmotic flux. This upper division biochemistry laboratory project is a challenging and rewarding one that exposes students to a biomolecule (lipid) and a spectroscopic technique (laser spectroscopy) that are not commonly used in the undergraduate laboratory setting. © 2019 International Union of Biochemistry and Molecular Biology, 47(3):239–246, 2019.

show abstract

Phase transitions in phospholipid bilayers: Lateral phase separations play vital roles in biomembranes

Cited by 41 publications

References 14 publications

The effect of temperature on supported dipalmitoylphosphatidylcholine (DPPC) bilayers: Structure and lubrication performance

The effect of temperature on supported dipalmitoylphosphatidylcholine (DPPC) bilayers: Structure and lubrication performance

Wettability of Binary Solid-Supported Films of Zwitterionic/Anionic Phospholipids

Liposome permeability probed by laser light scattering

Contact Info

Product

Resources

About