◾ DSC Studies on the Modulation of Membrane Lipid Polymorphism and Domain Organization by Antimicrobial Peptides

2016 ◽  
pp. 185-206
Keyword(s):  
Antimicrobial Peptides ◽  
Membrane Lipid ◽  
Domain Organization ◽  
Dsc Studies ◽  
Lipid Polymorphism

scholarly journals Life without air

2020 ◽  
Vol 295 (13) ◽  
pp. 4124-4133
Author(s):  
Howard Goldfine
Keyword(s):  
Physical Chemistry ◽  
Membrane Lipid ◽  
Early Exposure ◽  
Human Pathogen ◽  
Lipid Biochemistry ◽  
Animal Cells ◽  
Cellular Regulation ◽  
Gram Positive Bacteria ◽  
Aerobic Process ◽  
Lipid Polymorphism

An early exposure to lipid biochemistry in the laboratory of Konrad Bloch resulted in a fascination with the biosynthesis, structures, and functions of bacterial lipids. The discovery of plasmalogens (1-alk-1′-enyl, 2-acyl phospholipids) in anaerobic Gram-positive bacteria led to studies on the physical chemistry of these lipids and the cellular regulation of membrane lipid polymorphism in bacteria. Later studies in several laboratories showed that the formation of the alk-1-enyl ether bond involves an aerobic process in animal cells and thus is fundamentally different from that in anaerobic organisms. Our work provides evidence for an anaerobic process in which plasmalogens are formed from their corresponding diacyl lipids. Studies on the roles of phospholipases in Listeria monocytogenes revealed distinctions between its phospholipases and those previously discovered in other bacteria and showed how the Listeria enzymes are uniquely fitted to the intracellular lifestyle of this significant human pathogen.

scholarly journals Small heat-shock proteins regulate membrane lipid polymorphism

2002 ◽  
Vol 99 (21) ◽  
pp. 13504-13509 ◽  
Author(s):  
N. M. Tsvetkova ◽  
I. Horvath ◽  
Z. Torok ◽  
W. F. Wolkers ◽  
Z. Balogi ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Membrane Lipid ◽  
Small Heat Shock Proteins ◽  
Lipid Polymorphism ◽  
Shock Proteins

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

Antimicrobial peptides in COPD

Pneumologie ◽  
2009 ◽  
Vol 63 (S 01) ◽  
Author(s):  
G Günther ◽  
E Andresen ◽  
J Bullwinkel ◽  
C Lange ◽  
H Heine
Keyword(s):  
Antimicrobial Peptides

Inhibition of Platelet Aggregation by Ethanol in Vitro Shows Specificity for Aggregating Agent Used and Is Influenced by Platelet Lipid Composition

1982 ◽  
Vol 48 (01) ◽  
pp. 049-053 ◽  
Author(s):  
C G Fenn ◽  
J M Littleton
Keyword(s):  
Platelet Aggregation ◽  
Lipid Composition ◽  
Saturated Fatty Acids ◽  
Calcium Ionophore ◽  
Cholesterol Content ◽  
Membrane Lipid ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Increased Sensitivity

SummaryEthanol at physiologically tolerable concentrations inhibited platelet aggregation in vitro in a relatively specific way, which may be influenced by platelet membrane lipid composition. Aggregation to collagen, calcium ionophore A23187 and thrombin (low doses) were often markedly inhibited by ethanol, adrenaline and ADP responses were little affected, and aggregation to exogenous arachidonic acid was actually potentiated by ethanol. Aggregation to collagen, thrombin and A23187 was inhibited more by ethanol in platelets enriched with saturated fatty acids than in those enriched with unsaturated fats. Platelets enriched with cholesterol showed increased sensitivity to ADP, arachidonate and adrenaline but this increase in cholesterol content did not appear to influence the inhibition by ethanol of platelet responses. The results suggest that ethanol may inhibit aggregation by an effect on membrane fluidity and/or calcium mobilization resulting in decreased activity of a membrane-bound phospholipase.

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