The influence of cholesterol on multicomponent Langmuir monolayers imitating outer and inner leaflet of human erythrocyte membrane

Wydro, Paweł

doi:10.1016/j.colsurfb.2012.10.020

Cited by 17 publications

(15 citation statements)

References 41 publications

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“…Furthermore, since fatty acids or phospholipids usually present unsaturations in the hydrocarbon chains, the study of mixtures of saturated and unsaturated compounds is of interest. Recent articles on fatty acid systems with mixed saturated-unsaturated hydrocarbon chains are those of [33,34], and on phospholipids systems with mixed saturated-unsaturated hydrocarbon chains are those of [35][36][37][38][39][40][41][42][43][44]. The main achievements reported in these works will be commented in the discussion section, in connection with the results of the present work.…”

Section: Introductionsupporting

confidence: 54%

Thermodynamic Behaviour of Mixed Films of an Unsaturated and a Saturated Polar Lipid. (Oleic Acid-Stearic Acid and POPC-DPPC)

Torrent‐Burgués

2018

Colloids and Interfaces

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Mixed fatty acids or mixed phospholipids systems with saturated-unsaturated hydrocarbon chains are of biological interest. In this work, the monolayers of oleic acid-stearic acid (OA-SA) and palmitoyloleoylphosphatidylcholine-dipalmitoylphosphatidylcholine (POPC-DPPC) have been studied. From the surface pressure-area isotherms, elastic modulus values and virial equation coefficients can be obtained. Thermodynamic treatment also yields excess (G E ) and mixing (∆G mix ) free energies. Results indicate positive G E values, that is, molecular interactions in the mixed films are less favourable, due to the presence of unsaturation; however, the mixture is slightly favourable due to the entropic factor that affords positive ∆G mix values. For the OA-SA system, a high SA content and surface pressure facilitate the phase separation, even though a certain miscibility between both components still remains. For the POPC-DPPC system, the most favourable mixing conditions occur for X POPC ≈ 0.4. For these mixed systems, the values of the elastic modulus are more similar to those of more fluid components (OA or POPC); analysis of the virial coefficients shows that the b 1 virial coefficient values lie between those of the individual components and are higher than values suitable for an ideal mixing.

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Section: Introductionsupporting

confidence: 54%

Thermodynamic Behaviour of Mixed Films of an Unsaturated and a Saturated Polar Lipid. (Oleic Acid-Stearic Acid and POPC-DPPC)

Torrent‐Burgués

2018

Colloids and Interfaces

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“…31,32 On the contrary, CHOL formed condensed monolayers (Figure 1, cyan line) and exhibited a mean molecular area close to 42 Å 2 , similar to those found in the literature. 10,28,30 The incorporation of CHOL into DPPC monolayers led to the disappearance of the LE/LC coexistence region in the isotherms (Figure 1, circle and triangle) and their gradual shift to lower areas with respect to the curve for pure DPPC with increasing the CHOL/DPPC molar ratio. It is worth noting that the DPPC/CHOL 4:1 (molar ratio) monolayers showed a mean molecular area of 64 Å 2 , which was slightly higher than that of DPPC monolayers (62 Å 2 ), suggesting a more expanded monolayer at the LC phase.…”

Section: Resultsmentioning

confidence: 98%

“…It regulates the organization and fluidity of biological membranes and influences the catalytic activity and incorporation of membrane enzymes. 10,11,12 Bolean et al have shown that the CHOL/phospholipid molar ratio influences the fluidity of liposome membranes and the catalytic activity of membrane-anchored TNAP. 13,14 According to Hanada et al, the strong interactions among sphingolipids, CHOL and GPIanchored proteins are responsible for the difficulty in removing alkaline phosphatases from biological membranes.…”

Section: Introductionmentioning

confidence: 99%

Cholesterol Regulates the Incorporation and Catalytic Activity of Tissue-Nonspecific Alkaline Phosphatase in DPPC Monolayers

et al. 2019

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Matrix vesicles (MVs) are a special class of extracellular vesicles that drive bone and dentin mineralization by providing the essential enzymes and ions for the nucleation and propagation of mineral crystals. Tissue-nonspecific alkaline phosphatase (TNAP) is an integral protein of MV membrane and participates in biomineralization by hydrolyzing extracellular pyrophosphate (PP i)-a strong mineralization inhibitor-and forming inorganic phosphate (P i) necessary for the growth of mineral crystals inside MVs and their propagation once released in the extracellular matrix. MV membrane is enriched in cholesterol (CHOL), which influences the incorporation and activity of integral proteins in biologic membranes, however how CHOL controls the incorporation and activity of TNAP in MV membrane has not yet been elucidated. In the present study, Langmuir monolayers were used as a MV membrane biomimetic model to assess how CHOL affects TNAP incorporation and activity. Surface pressure-area (π-A) isotherms of binary dipalmitoilphosphatidylcholine (DPPC)/CHOL monolayers showed that TNAP incorporation increases with CHOL concentration. Infrared spectroscopy showed that CHOL influences the conformation and orientation of the enzyme. Optical-fluorescence micrographs of the monolayers revealed the tendency of TNAP to incorporate into CHOL-rich microdomains. These data suggest that TNAP penetrates more efficiently and occupies a higher surface area into monolayers with a lower CHOL concentration due to the higher membrane fluidity. However, the quantity of enzyme transferred to solid supports as well as the enzymatic activity were higher using monolayers with a higher CHOL concentration due to increased rigidity that changes the enzyme orientation at the air-solid interface. These data provide new insights regarding the interfacial behavior of TNAP and CHOL in MVs and shed the light on the biochemical and biophysical processes occurring in MV membrane during biomineralization at the molecular level.

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“…Schmidt et al [114] showed that the very slightly surface active protein- Langmuir monolayers of cholesterol/DPPC = 0.9 [117] or as more complicated ternary and quaternary mixtures [118] with different compositions of its inner and outer leaflets. Bacterial …”

Section: Other Polysaccharidesmentioning

confidence: 99%

Interactions of bioactive molecules & nanomaterials with Langmuir monolayers as cell membrane models

et al. 2015

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The influence of cholesterol on multicomponent Langmuir monolayers imitating outer and inner leaflet of human erythrocyte membrane

Cited by 17 publications

References 41 publications

Thermodynamic Behaviour of Mixed Films of an Unsaturated and a Saturated Polar Lipid. (Oleic Acid-Stearic Acid and POPC-DPPC)

Thermodynamic Behaviour of Mixed Films of an Unsaturated and a Saturated Polar Lipid. (Oleic Acid-Stearic Acid and POPC-DPPC)

Cholesterol Regulates the Incorporation and Catalytic Activity of Tissue-Nonspecific Alkaline Phosphatase in DPPC Monolayers

Interactions of bioactive molecules & nanomaterials with Langmuir monolayers as cell membrane models

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