Heating-Enabled Formation of Droplet Interface Bilayers Using Escherichia coli Total Lipid Extract

Langmuir ◽  
2014 ◽  
Vol 31 (1) ◽  
pp. 325-337 ◽  
Author(s):  
Graham J. Taylor ◽  
Stephen A. Sarles
Keyword(s):  
Escherichia Coli ◽  
Total Lipid ◽  
Lipid Extract ◽  
Total Lipid Extract

A fast way to track functional OmpF reconstitution in liposomes: Escherichia coli total lipid extract

2015 ◽  
Vol 479 ◽  
pp. 54-59 ◽  
Author(s):  
S.C. Lopes ◽  
M. Ferreira ◽  
C.F. Sousa ◽  
P. Gameiro
Keyword(s):  
Escherichia Coli ◽  
Total Lipid ◽  
Lipid Extract ◽  
Total Lipid Extract

scholarly journals Size-Dependent Interaction of Amyloid β Oligomers with Brain Total Lipid Extract Bilayer—Fibrillation Versus Membrane Destruction

Langmuir ◽  
2019 ◽  
Vol 35 (36) ◽  
pp. 11940-11949 ◽  
Author(s):  
Dusan Mrdenovic ◽  
Marta Majewska ◽  
Izabela S. Pieta ◽  
Piotr Bernatowicz ◽  
Robert Nowakowski ◽  
...  
Keyword(s):  
Total Lipid ◽  
Amyloid Β ◽  
Lipid Extract ◽  
Total Lipid Extract ◽  
Size Dependent ◽  
Dependent Interaction

Copper Modulation of Amyloid Beta 42 Interactions with Model Membranes

2012 ◽  
Vol 65 (5) ◽  
pp. 472 ◽  
Author(s):  
Daniel K. Weber ◽  
John D. Gehman ◽  
Frances Separovic ◽  
Marc-Antoine Sani
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Total Lipid ◽  
Acyl Chain ◽  
Amyloid Β ◽  
Neuronal Cell ◽  
Model Systems ◽  
Lipid Extract ◽  
Total Lipid Extract ◽  
Amyloid Β Peptide

Growing evidence supports that interactions of the amyloid-β peptide Aβ(1–42) with neuronal cell membranes and copper are involved in Alzheimer’s disease pathogenesis. We report using solid-state NMR that the peptide significantly perturbed the phosphate and upper acyl chain region of bilayers comprising brain total lipid extract to cause domain segregation. Deep headgroup perturbations were also realized for palmitoyloleoylphospatidylcholine–cholesterol model systems; however, incorporating 10 % palmitoyloleoylphosphatidylserine or the ganglioside GM1 resulted in a more peripheral interaction. Cu2+ at a 1 : 7 molar ratio to peptide caused deeper penetration into model systems, but partially attenuated interactions with brain total lipid extract. Thioflavin T assay showed that bilayers affected amyloid formation in a mode dependant on lipid content, and was further modulated by addition of Cu2+. Our data support that ternary interactions between Cu2+, lipids and Aβ(1–42) may have significance in Alzheimer’s disease, and challenge the validity of model bilayers as substitutes for natural systems.

Direct thin-layer chromatography of gangliosides of a total lipid extract

1978 ◽  
Vol 86 (2) ◽  
pp. 543-551 ◽  
Author(s):  
S. Harth ◽  
H. Dreyfus ◽  
P.F. Urban ◽  
P. Mandel
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Total Lipid ◽  
Lipid Extract ◽  
Total Lipid Extract ◽  
Layer Chromatography

scholarly journals THE ACTION OF FORMALDEHYDE SOLUTIONS ON HUMAN BRAIN LIPIDS

1962 ◽  
Vol 10 (6) ◽  
pp. 704-709 ◽  
Author(s):  
F. J. M. HESLINGA ◽  
F. A. DEIERKAUF
Keyword(s):  
Fatty Acid ◽  
Human Brain ◽  
Total Lipid ◽  
Fatty Acid Content ◽  
Total Lipid Content ◽  
Water Soluble ◽  
Lipid Extract ◽  
Total Lipid Extract ◽  
Brain Lipids ◽  
Marked Diminution

The composition of the lipids extracted from fresh normal human brain and from brains preserved up to 24 years in unbuffered formaldehyde solutions was analysed quantitatively using column and paper chromatography, followed by various determinations. The amounts of cholesterol, cerebrosides, sulphatides, phosphoinositides and sphingomyelin remain unaffected. Lecithin, phosphatidylethanolamine and phosphatidylserine are broken down to the corresponding lyso compounds, fatty acids, phosphatidic acid and probably lysophosphatidic acid. The lyso compounds are further broken down by the liberation of the second fatty acid. By this process the fatty acid content is markedly increased. The total lipid content decreases slightly by the formation of water soluble phosphoryl compounds. Consequently the phosphorus content of the total lipid extract suffers marked diminution. Histochemical reactions on lipids in formaldehyde stored tissues should preferably be performed in combination with an analysis of the lipid extract.

Model Neural Membrane Droplet Interface Bilayers from Brain Total Lipid Extract for Studying Membrane-Peptide Interactions with Amyloid-β

2015 ◽  
Vol 1722 ◽  
Author(s):  
Graham J. Taylor ◽  
Stephen A. Sarles
Keyword(s):  
Total Lipid ◽  
Single Channel ◽  
Amyloid Β ◽  
Helical Structure ◽  
Lipid Extract ◽  
Neural Cells ◽  
Total Lipid Extract ◽  
Electrical Measurements ◽  
Aβ Oligomers ◽  
Significant Difference

ABSTRACTDroplet interface bilayers (DIBs) are formed using brain total lipid extract (BTLE) to create a synthetic bilayer whose lipid composition mimics that of neural cells. The electrical properties of BTLE DIBs, specifically membrane resistance, capacitance, and rupture potential, are determined and compared to the properties of bilayers formed using DPhPC, the most common lipid within the growing DIB field. There is no significant difference in the resistance or rupture potential of BTLE and DPhPC bilayers, for instance with average nominal resistance over 200 GΩ and rupture potential around 200 mV. In electrical measurements with either DPhPC or BTLE bilayers, applied voltages of up to ±150 mV yield low levels of leakage current. Upon interaction with the pore-forming amyloid-beta (Aβ) peptide, both bilayers display sudden significant voltage-dependent increases in conductance with characteristic threshold voltages well below 150 mV. Discrete single-channel type events are observed in the case of Aβ-BTLE whereas disordered fluctuating conductance is observed with Aβ-DPhPC. Circular dichroism is measured for Aβ incubated with BTLE and DPhPC liposomes, as well as pure Aβ, at a range of temperatures over a period of several weeks. Changes in secondary structure of liposome-bound and pure Aβ are significantly affected by both lipid type and temperature. A key finding includes the 100% conversion of Aβ to alpha-helical confirmation within 24 hours when incubated with liposomes (of either type) at physiologically relevant 37°C. The 100% alpha-helical Aβ is maintained for up to 2 weeks at 37°C when incubated with liposomes, although other structures begin to emerge after the 14 day mark. Between 14-31 days after reconstitution, Aβ incubated at 37C with BTLE bilayers displays longer lasting alpha-helical content than DPhPC. At the same temperature, pure Aβ is 100% alpha helical only at the 1 day mark with apparent restructuring from day 2 through day 31. Refrigerated Ab samples do not display 100% alpha-helical structure across the entire 31 day testing period. The differences observed between BTLE and DPhPC in both electrophysiological and spectroscopic experiments may be a result of phase separations or other variations in membrane fluidity that result from the use of a homogeneous total lipid extract. Time and temperature play essential roles in the aggregation and restructuring of potentially toxic Aβ oligomers, and there is motivation for further efforts to elicit the mechanistic differences in interactions of Ab with BTLE compared to DPhPC.

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