In the present study, the influence of the phospholipid phase state on the activity of the xanthophyll cycle enzyme violaxanthin de-epoxidase (VDE) was analyzed using different phosphatidylethanolamine species as model lipids. By using (31)P NMR spectroscopy, differential scanning calorimetry and temperature dependent enzyme assays, VDE activity could directly be related to the lipid structures the protein is associated with. Our results show that the gel (L beta) to liquid-crystalline (L alpha) phase transition in these single lipid component systems strongly enhances both the solubilization of the xanthophyll cycle pigment violaxanthin in the membrane and the activity of the VDE. This phase transition has a significantly stronger impact on VDE activity than the transition from the L alpha to the inverted hexagonal (HII) phase. Especially at higher temperatures we found increased VDE reaction rates in the presence of the L alpha phase compared to those in the presence of HII phase forming lipids. Our data furthermore imply that the HII phase is better suited to maintain high VDE activities at lower temperatures.
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http://dx.doi.org/10.1016/j.bbamem.2007.12.002 | DOI Listing |
JAMA
January 2025
Worcestershire Royal Hospital, Worcester, United Kingdom.
Importance: Patients undergoing unplanned abdominal surgical procedures are at increased risk of surgical site infection (SSI). It is not known if incisional negative pressure wound therapy (iNPWT) can reduce SSI rates in this setting.
Objective: To evaluate the effectiveness of iNPWT in reducing the rate of SSI in adults undergoing emergency laparotomy with primary skin closure.
Deep eutectic solvents are highly tailorable non-aqueous solvents with potential applications ranging from energy catalysis to cryopreservation. Self-assembled lipid structures are already used in a variety of industries including cosmetics, drug delivery and as microreactors. However, most research into lipid self-assembly has been limited to aqueous solvents.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, 8093, Switzerland.
The translation of cell-derived extracellular vesicles (EVs) into biogenic gene delivery systems is limited by relatively inefficient loading strategies. In this work, the loading of various nucleic acids into small EVs via their spontaneous hybridization with preloaded non-lamellar liquid crystalline lipid nanoparticles (LCNPs), forming hybrid EVs (HEVs) is described. It is demonstrated that LCNPs undergo pH-dependent structural transitions from inverse hexagonal (H) phases at pH 5 to more disordered non-lamellar phases, possibly inverse micellar (L) or sponge (L) phases, at pH 7.
View Article and Find Full Text PDFTrends Parasitol
January 2025
Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand; HSM, University of Montpellier, CNRS, IRD, Montpellier, France. Electronic address:
Success in the national control of malaria during the past decades has led to the reorientation of Thailand's program toward the elimination of this disease. The country established and implemented a National Malaria Elimination Strategy, resulting in a substantial decline in cases. Although the reduction varied, Sisaket Province stands out as a success.
View Article and Find Full Text PDFAm J Physiol Lung Cell Mol Physiol
December 2024
Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon, United States.
To function effectively, pulmonary surfactant must adsorb rapidly to the alveolar air/water interface but avoid collapse from the surface when compressed to high interfacial densities. Prior studies show that phospholipids in the cylindrical monolayers of the inverse hexagonal (H) phase adsorb quickly. The monolayers have negative curvature, defined by the concave shape of the hydrophilic face.
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