Membrane lipids, and especially phosphoinositides, are differentially enriched within the eukaryotic endomembrane system. This generates a landmark code by modulating the properties of each membrane. Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P] specifically accumulates at the plasma membrane in yeast, animal, and plant cells, where it regulates a wide range of cellular processes including endocytic trafficking.
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July 2022
In this study, water vapor sorption, desorption properties and tensile mechanical properties of four cellulosic fibers, cotton (C), flax (F), viscose (V) and cellulose acetate (CA), were determined. The sorption and desorption isotherms were modeled using the Park model, which allowed an accurate fitting on the whole range of water activity. This model corresponds to a multi-sorption mode dividing in three sorption modes: Langmuir sorption, Henry's law and water clustering.
View Article and Find Full Text PDFMembrane surface charge is critical for the transient, yet specific recruitment of proteins with polybasic regions to certain organelles. In eukaryotes, the plasma membrane (PM) is the most electronegative compartment of the cell, which specifies its identity. As such, membrane electrostatics is a central parameter in signaling, intracellular trafficking, and polarity.
View Article and Find Full Text PDFPurpose: Beyond promising experimental results of sensory passive stimulations in spatial cognition disorders, some questions still remain regarding interests of these stimulations during the daily activities in neglect. The aim of this case-study was to evaluate the effects of a protocol combining left neck-muscle vibration with daily simple movements, like arm pointing movements, on perceptivo-locomotor deficits in a left spatial neglect patient.
Materials And Methods: Two neuropsychological tests, one subjective straight-ahead pointing (SSA) test and one wheelchair navigation test were carried out before the combination protocol, immediately after, 1 h later, and 24 h later.
Many signalling proteins permanently or transiently localize to specific organelles. It is well established that certain lipids act as biochemical landmarks to specify compartment identity. However, they also influence membrane biophysical properties, which emerge as important features in specifying cellular territories.
View Article and Find Full Text PDFPhosphatidylinositolphosphates (PIPs) are phospholipids that contain a phosphorylated inositol head group. PIPs represent a minor fraction of total phospholipids, but are involved in many regulatory processes, such as cell signalling and intracellular trafficking. Membrane compartments are enriched or depleted in specific PIPs, providing a unique composition for these compartments and contributing to their identity.
View Article and Find Full Text PDFMatrix-Assisted Laser Desorption/Ionization time-of-flight (MALDI-TOF) mass spectrometry is evaluated as an elucidation tool for structural features and molecular weights estimation of some extracted herbaceous lignins. Optimization of analysis conditions, using a typical organic matrix, namely α-cyano-4-hydroxycinnamic acid (CHCA), in combination with α-cyclodextrin, allows efficient ionization of poorly soluble lignin materials and suppression of matrix-related ions background. Analysis of low-mass fragments ions (m/z 100-600) in the positive ion mode offers a "fingerprint" of starting lignins that could be a fine strategy to qualitatively identify principal inter-unit linkages between phenylpropanoid units.
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