Surface thermodynamics study of monolayers formed with heteroacid phospholipids of biological interest

Doménech, Òscar; Torrent‐Burgués, J.; Merino, Sandra; Sanz, Fausto; Montero, M. Teresa; Hernández-Borrell, Jordi

doi:10.1016/j.colsurfb.2004.12.012

Cited by 27 publications

(25 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…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: Introductionmentioning

confidence: 64%

“…Comparing the behaviour of the POPC-DPPC mixed films with that of the unsaturated phospholipids POPC-POPE [35], it is shown that POPC-POPE mixed films demonstrate favourable mixing at all compositions, with negative values of the excess area, A E , and with more negative values of the mixing energy, ∆G mix . Comparing the values of the virial coefficient b 1 for DPPC, POPC and POPE [35], it was observed that DPPC presents the lowest value.…”

Section: Discussionmentioning

confidence: 99%

“…The virial state equation is useful and allows, through the virial coefficients, for an examination of molecular interactions [35,50]; in this case, it will be applied to the effect of an unsaturation in the acyl chain over the molecular interactions. The value of b 0 is attributed to the aggregation state of the film-forming molecules, and the value of b 1 provides information about the exclusion volumes and the interaction between the molecules in the film.…”

Section: Introductionmentioning

confidence: 99%

“…The value of b 0 is attributed to the aggregation state of the film-forming molecules, and the value of b 1 provides information about the exclusion volumes and the interaction between the molecules in the film. The following treatment can be applied to the virial coefficients in a mixture [35], where X refers to the molar fraction, the subscripts 1 and 2 refer to the individual components, the subscripts m and 12 refer to the mixture, and the superscripts id and E referring to an ideal behaviour and to an excess magnitude, respectively: b 1)m = b 1)1 ·X 1 2 + b 1)2 ·X 2 2 + 2b 1)12 ·X 1 ·X 2 (3)…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Introductionmentioning

confidence: 64%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Self Cite

View full text Add to dashboard Cite

show abstract

“…13 mN·m -1 . Inset of Figure 1 gives a clearer view of inflexion points and also permits to assign the film state according to the C In the case of a mixed monolayer of two components, ΔG mix can be expressed as [43,44]:…”

Section: Brewster Angle Microscopy (Bam)mentioning

confidence: 99%

Biomimetic monolayer films of monogalactosyldiacylglycerol incorporating ubiquinone

Hoyo

Torrent‐Burgués

Guaus

2012

Journal of Colloid and Interface Science

Self Cite

View full text Add to dashboard Cite

Ubiquinone and plastoquinone are two of the main electron and proton shuttle molecules in biological systems, and monogalactosyldiacylglycerol (MGDG) is the most abundant lipid in the thylakoid membrane of chloroplasts. Saturated MGDG, ubiquinone-10 (UQ) and MGDG:UQ mixed monolayers at the air/water interface have been studied using Surface Pressure-Area isotherms and Brewster Angle Microscopy. Moreover, the transferred Langmuir-Blodgett films have been observed by Atomic Force Microscopy. The results show that MGDG:UQ mixtures present more fluid phase than pure MGDG indicating a higher order degree for the later. It is also observed an important influence of UQ on the MGDG matrix before UQ collapse pressure and a low influence after this event, due to UQ expulsion from the MGDG matrix. This expulsion leads to a similar remaining UQ content for all the tested mixtures, indicating a limiting content of this molecule in the MGDG matrix at high surface pressures. The thermodynamic studies confirm the stability of the MGDG:UQ mixtures at low surface pressures, although presenting a non-ideal behaviour. Results point to consider UQ as a good candidate for studies of artificial photosynthesis.

show abstract

Atomic force microscopy characterization of supported planar bilayers that mimic the mitochondrial inner membrane

Doménech

Redondo²,

Picas³

et al. 2007

J of Molecular Recognition

Self Cite

View full text Add to dashboard Cite

In this study we examined the properties of supported planar bilayers (SPBs) formed from phospholipid components that comprise the mitochondrial inner membrane. We used 1-palmitoyl-2-oleoyl-sn-glycero- 3-phosphocholine (POPC), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) and cardiolipin (CL). Liposomes of binary POPE:POPC (1:1, mol:mol) and ternary (POPE:POPC:CL (0.5:0.3:0.2, mol:mol:mol) composition were used in the formation of SPBs on mica. The characterization of the SPBs was carried out below (4 degrees C) and above (24 and 37 degrees C) the phase transition temperature (Tm) of the mixtures in solution. We observed: (i) that the thickness of the bilayers, calculated from a cross-sectional analysis, decreased as the visualization temperature increased; (ii) the existence of laterally segregated domains that respond to temperature in SPBs of POPE:POPC:CL; (iii) a decrease in height and an increase in roughness (Ra) of SPBs after cytochrome c (cyt c) injection at room temperature. To obtain further insight into the nature of the interaction between cyt c and the bilayers, the competition between 8-anilino-1-naphthalene sulfonate (ANS) and the protein for the same binding sites in liposomes was monitored by fluorescence. The results confirm the existence of preferential interaction of cyt c with CL containing liposomes. Taking these results and those of previous papers published by the group, we discuss the preferential adsorption of cyt c in CL domains. This provides support for the relevance of these phospholipids as a proton trap in the oxidative phosphorylation process that occurs in the energy transducing membranes.

show abstract

Surface thermodynamics study of monolayers formed with heteroacid phospholipids of biological interest

Cited by 27 publications

References 34 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)

Biomimetic monolayer films of monogalactosyldiacylglycerol incorporating ubiquinone

Atomic force microscopy characterization of supported planar bilayers that mimic the mitochondrial inner membrane

Contact Info

Product

Resources

About