Search results for "phospholipid"

Involvement of plasmalogens and polyunsaturated fatty acids in the pathogenesis of glaucoma

2013

Cyclopropane Fatty Acid Synthase from Oenococcus oeni: Expression in Lactococcus lactis subsp. Cremoris and Biochemical Characterization

2015

Bacterial cyclopropane fatty acid synthases (CFA synthases) catalyze the transfer of a methyl group from S-adenosyl-L-methionine (AdoMet) to the double bond of a lipid chain, thereby forming a cyclopropane ring. CFAs contribute to resistance to acidity, dryness, and osmotic imbalance in many bacteria. This work describes the first biochemical characterization of a lactic acid bacterium CFA synthase. We have overexpressed Oenococcus oeni CFA synthase in E. coli in order to purify the enzyme. The optimum cyclopropanation activity was obtained at pH 5.6 and 35.8 °C. The high K(m) (AdoMet) value obtained (2.26 mM) demonstrates the low affinity of O. oeni enzyme toward the L. lactis subsp. cremo…

Regulation of the synthesis of aryl metabolites by phospholipid sources in the white-rot fungus Bjerkandera adusta

1999

The white-rot basidiomycete Bjerkandera adusta was cultivated in a liquid medium enriched with l-phenylalanine and various phospholipid sources (lecithin, egg yolk and asolectin). Three aromatic metabolites (benzaldehyde, benzyl alcohol and benzoic acid) were produced under these culture conditions. High concentrations of benzaldehyde (404 mg l–1) were obtained when the cultures were supplemented with 10 g lecithin l–1. Benzyl alcohol production was promoted when the strain was grown with 5 or 10 g lecithin l–1. In the absence of or with a low concentration of lecithin (2.5 g l–1), benzoic acid was the major aryl metabolite synthesized. The results presented here indicate that aryl alcohol …

Catastrophic antiphospholipid syndrome in a patient with V Leiden variant

2012

The lipid composition, fluidity, and Mg2+-ATPase activity of rice (Oryza sativa L. cv. Bahia) shoot plasma membranes: effects of ABA and GA3

1992

Six-day-old rice plants (Oryza sativa L., cv Bahia) were grown for 5 days more in nutrient solution culture containing 10−5 M abscisic acid (ABA) or gibberellic acid (GA3) (treated plants). Plasma membrane (PM) vesicles were isolated from the shoots of treated or control plants, and ATPase hydrolytic and proton-pumping activity, fluidity, and free sterol and phospholipid composition were determined. Both treatments resulted in modified plant growth and increases in PM fluidity. The ATPase hydrolytic activity was decreased by 25% of control values with ABA treatment and by 35% with GA3. Both treatments reduced proton-pumping by 23%. GA3 treatment reduced the relative amount (%) of stigmaster…

Clinical relevance of antiphospholipid antibodies in primary biliary cirrhosis.

2005

Primary biliary cirrhosis (PBC) is a cholestatic liver disease characterized by the presence of antimitochondrial autoantibodies (AMAs), but also with reactivities to other autoantigens. Recent studies showed that antibodies to phospholipids (APAs) represent an important group of autoantibodies identified in patients with PBC. In this study different types of APAs were identified in the sera of patients with PBC and autoimmune hepatitis (AIH) and control subjects. Sera from patients with PBC and AIH were tested for the presence of antibodies directed against cardiolipin (CL), phosphatidylserine (PS), and to beta(2)-glycoprotein I (beta(2)-GPI). Furthermore, an in-house test for antithrombop…

The binding of G-protein to rod outer segment phospholipids at the nitrogen–water interface

1989

In the visual process, one photoexcited rhodopsin (R*) catalyzes the activation of hundreds of G-proteins. It remains to be determined whether G-protein and R* find one another by membrane surface diffusion of these components (diffusion model) or by diffusion of G-protein through the aqueous phase (hopping model). A monolayer of each main rod outer segment (ROS) phospholipid interacting with a subphase containing G-protein, has been used to simulate the interaction of G-protein with the cytoplasmic surface of discal membranes. The possible diffusion of G-protein through the aqueous phase was then measured by observing its adsorption–desorption in the monolayer of each main ROS phospholipi…

In Vitro Effects of Antiphospholipid Syndrome-IgG Fractions and Human Monoclonal Antiphospholipid IgG Antibody on Human Umbilical Vein Endothelial Ce…

2009

It has been shown that stimulation of endothelial cells and monocytes by antiphospholipid antibodies leads to a prothrombotic state involving upregulation of tissue factor (TF). We examined the in vitro effects of IgG fractions from patients with antiphospholipid syndrome (APS) and of a β-2-glycoprotein 1-independent human monoclonal antiphospholipid antibody (HL-5B) on human umbilical vein endothelial cells (HUVEC) in comparison to untreated cell controls and to exposure to monoclonal IgG control antibody. We also examined the effect of recombinant monocyte chemoattractant protein-1 (MCP-1) on peripheral blood monocytes. Stimulation of endothelial cells with APS IgG fractions or HL-5B resu…

Toll-like receptors play a crucial part in the pathophysiological activity of antiphospholipid antibodies

2011

The antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by thrombosis, recurrent fetal loss and the presence of a variety of antiphospholipid antibodies (aPL), directed to phospholipids like Cardiolipin and phospholipid binding proteins like β2-glycoprotein I. Till date, the pathophysiological processes underlying these thrombotic events were still not fully understood. Recent data support the idea that the aPL might act via enhanced cytokine release due to activation of certain Toll-like receptors. The investigation of some of those mechanisms in more detail enlightens the involvement of the intracellular receptors TLR7 and TLR8 in a central point. Using patients…

1996

18:2Δ 9c,12t and 18:2 Δ9t,12c are present in our diet, as result of heat treatment of vegetable oils. A nutritional study was carried out in order to obtain more precise information on the conversion of these two isomers into long chain polyunsaturated fatty acids (PUFA) by rat tissues. This in vivo study performed using rat fed with small quantities of mono trans linoleic acid isomers (0.6% of total energy) showed that 18:2 Δ9c,12t was converted into 20:4 Δ5c,8c,11c,14t while 18:2 Δ9t,12c was only slightly converted into 20:4 Δ5c,8c,11t,14c. Furthermore 18:2 Δ9t,12c was preferentially elongated into 20:2 Δ11t,14c. Each C20 metabolite of these mono trans 18:2 isomers was isolated as methyl …