CD81 extracted in SMALP nanodiscs comprises two distinct protein populations within a lipid environment enriched with negatively charged headgroups.

Tetraspanins exert a wide range of cellular functions of broad medical importance. Despite this, their biophysical characteristics are incompletely understood. Only two high-resolution structures of full-length tetraspanins have been solved.

Inflammation, Lipid (Per)oxidation, and Redox Regulation.

Inflammation increases during the aging process. It is linked to mitochondrial dysfunction and increased reactive oxygen species (ROS) production. Mitochondrial macromolecules are critical targets of oxidative damage; they contribute to respiratory uncoupling with increased ROS production, redox stress, and a cycle of senescence, cytokine production, and impaired oxidative phosphorylation.

Anaerobiosis influences virulence properties of Pseudomonas aeruginosa cystic fibrosis isolates and the interaction with Staphylococcus aureus.

The airways of individuals with cystic fibrosis (CF) are abundantly colonised by Staphylococcus aureus and Pseudomonas aeruginosa. Co-infecting hypoxic regions of static mucus within CF airways, together with decreases in pulmonary function, mucus plugging and oxygen consumption by host neutrophils gives rise to regions of anoxia. This study determined the impact of anaerobiosis upon S.

Apoptotic cell-derived extracellular vesicles: structure-function relationships.

Apoptosis is an essential process for normal physiology and plays a key role in the resolution of inflammation. Clearance of apoptotic cells (ACs) involves complex signalling between phagocytic cells, ACs, and the extracellular vesicles (EVs) they produce. Here, we discuss apoptotic cell-derived extracellular vesicles (ACdEVs) and how their structure relates to their function in AC clearance and the control of inflammation, focussing on the ACdEV proteome.

Communicating with the dead: lipids, lipid mediators and extracellular vesicles.

Apoptosis is a key event in the control of inflammation. However, for this to be successful, dying cells must efficiently and effectively communicate their presence to phagocytes to ensure timely removal of dying cells. Here, we consider apoptotic cell-derived extracellular vesicles and the role of contained lipids and lipid mediators in ensuring effective control of inflammation.

Simvastatin reduces circulating oxysterol levels in men with hypercholesterolaemia.

Oxysterols (OHC) are biologically active cholesterol metabolites circulating in plasma that may be formed enzymatically (e.g. 24S-OHC, 25-OHC and 27-OHC) or by autoxidative mechanisms (e.

Technical challenges of working with extracellular vesicles.

Extracellular Vesicles (EVs) are gaining interest as central players in liquid biopsies, with potential applications in diagnosis, prognosis and therapeutic guidance in most pathological conditions. These nanosized particles transmit signals determined by their protein, lipid, nucleic acid and sugar content, and the unique molecular pattern of EVs dictates the type of signal to be transmitted to recipient cells. However, their small sizes and the limited quantities that can usually be obtained from patient-derived samples pose a number of challenges to their isolation, study and characterization.

Porphyromonas gingivalis gingipains cause defective macrophage migration towards apoptotic cells and inhibit phagocytosis of primary apoptotic neutrophils.

Periodontal disease is a prevalent chronic inflammatory condition characterised by an aberrant host response to a pathogenic plaque biofilm resulting in local tissue damage and frustrated healing that can result in tooth loss. Cysteine proteases (gingipains) from the key periodontal pathogen Porphyromonas gingivalis have been implicated in periodontal disease pathogenesis by inhibiting inflammation resolution and are linked with systemic chronic inflammatory conditions such as rheumatoid arthritis. Efficient clearance of apoptotic cells is essential for the resolution of inflammation and tissue restoration.

Recent Advances on Mass Spectrometry Analysis of Nitrated Phospholipids.

In recent years, there has been an increasing interest in nitro fatty acids (NO2-FA) as signaling molecules formed under nitroxidative stress. NO2-FA were detected in vivo in a free form, although it is assumed that they may also be esterified to phospholipids (PL). Nevertheless, insufficient discussion about the nature, origin, or role of nitro phospholipids (NO2-PL) was reported up to now.

Separation and characterization of oxidized isomeric lipid-peptide adducts by ion mobility mass spectrometry.

Phospholipids are major components of cell membranes and lipoprotein complexes. They are prone to oxidation by endogenous and exogenous reactive oxygen species yielding a large variety of modified lipids including small aliphatic and phospholipid bound aldehydes and ketones. These carbonyls are strong electrophiles that can modify proteins and, thereby, alter their structures and functions triggering various pathophysiological conditions.

Profiling and relative quantification of multiply nitrated and oxidized fatty acids.

The levels of nitro fatty acids (NO2-FA), such as nitroarachidonic, nitrolinoleic, nitrooleic, and dinitrooleic acids, are elevated under various inflammatory conditions, and this results in different anti-inflammatory effects. However, other multiply nitrated and nitro-oxidized FAs have not been studied so far. Owing to the low concentrations in vivo, NO2-FA analytics usually relies on targeted gas chromatography-tandem mass spectrometry (MS/MS) or liquid chromatography-MS/MS, and thus require standard compounds for method development.

Heterogeneity of peptide adducts with carbonylated lipid peroxidation products.

Highly reactive lipid peroxidation-derived carbonyls (oxoLPP) modify protein nucleophiles via Michael addition or Schiff base formation. Once formed, Michael adducts can be further stabilized via cyclic hemiacetals with or without loss of water. Depending on the mechanism of their formation, peptide-oxoLPP can carry aldehyde or keto groups and thus be a part of the total protein carbonylation level.

Identification of carbonylated lipids from different phospholipid classes by shotgun and LC-MS lipidomics.

Oxidized lipids play a significant role in the pathogenesis of numerous oxidative stress-related human disorders, such as atherosclerosis, obesity, inflammation, and autoimmune diseases. Lipid peroxidation, induced by reactive oxygen and nitrogen species, yields a high variety of modified lipids. Among them, carbonylated lipid peroxidation products (oxoLPP), formed by oxidation of the fatty acid moiety yielding aldehydes or ketones (carbonyl groups), are electrophilic compounds that are able to modify nucleophilic substrates like proteins, nucleic acid, and aminophospholipids.

Derivatization and detection of small aliphatic and lipid-bound carbonylated lipid peroxidation products by ESI-MS.

Double bonds in polyunsaturated fatty acids (PUFA) and lipids are one of the major targets of reactive oxygen species (ROS). The resulting lipid peroxidation products (LPP) represent a group of chemically diverse compounds formed by several consecutive oxidative reactions. Oxidative cleavage leads to the formation of small aliphatic and lipid-bound aldehydes and ketones (oxoLPPs).

Simultaneous detection of low and high molecular weight carbonylated compounds derived from lipid peroxidation by electrospray ionization-tandem mass spectrometry.

Reactive oxygen species (ROS) and other oxidative agents such as free radicals can oxidize polyunsaturated fatty acids (PUFA) as well as PUFA in lipids. The oxidation products can undergo consecutive reactions including oxidative cleavages to yield a chemically diverse group of products, such as lipid peroxidation products (LPP). Among them are aldehydes and ketones ("reactive carbonyls") that are strong electrophiles and thus can readily react with nucleophilic side chains of proteins, which can alter the protein structure, function, cellular distribution, and antigenicity.

Characterization of oxidation products from 1-palmitoyl-2-linoleoyl-sn-glycerophosphatidylcholine in aqueous solutions and their reactions with cysteine, histidine and lysine residues.

This report focuses on studies of lipid peroxidation products reactivity towards the side chains of cysteine, histidine, and lysine residues in structurally unordered peptides. Thus we have analyzed linoleic acid peroxidation products (LaPP) obtained by incubating 1-palmitoyl-2-linoleoyl-sn-glycerophosphatidylcholine (PLPC) overnight with or without H(2)O(2) in the presence or absence of CuCl. In total, 55 different LaPP were identified with 26 containing reactive carbonyl groups.