Effects of cholesterol on acyl chain dynamics in multilamellar vesicles of various phosphatidylcholines

Kutchai, Howard; Chandler, Laura H.; Zavoico, George B.

doi:10.1016/0005-2736(83)90277-8

Cited by 65 publications

(37 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The triacylglyerol fatty acyl composition of both ConAresolved LD was also determined, but although it was established that both LD fractions were significant reservoirs of C16:0, C18:1, C18:0, and C18:3, in keeping with literature on mouse adipose tissue (20,72), no consistent trend was otherwise observed. Taken together, these results indicated an increased rigidity or higher lipid order in the phospholipid monolayer found in perilipin-enriched LD (60). It was also noteworthy that levels of several phospholipids such as SM, PC, and PI were significantly enriched in the perilipin-enriched LD fraction, with little to no differences observed in PE or PS levels compared with nonbinding LD fractions.…”

Section: Discussionmentioning

confidence: 62%

The phospholipid monolayer associated with perilipin-enriched lipid droplets is a highly organized rigid membrane structure

Storey¹,

McIntosh²,

Senthivinayagam

et al. 2011

American Journal of Physiology-Endocrinology and Metabolism

View full text Add to dashboard Cite

(LD) in lipid metabolism, cell signaling, and membrane trafficking is increasingly recognized, yet the role of the LD phospholipid monolayer in LD protein targeting and function remains unknown. To begin to address this issue, two populations of LD were isolated by ConA sepharose affinity chromatography: 1) functionally active LD enriched in perilipin, caveolin-1, and several lipolytic proteins, including ATGL and HSL; and 2) LD enriched in ADRP and TIP47 that contained little to no lipase activity. Coimmunoprecipitation experiments confirmed the close association of caveolin and perilipin and lack of interaction between caveolin and ADRP, in keeping with the separation observed with the ConA procedure. The phospholipid monolayer structure was evaluated to reveal that the perilipin-enriched LD exhibited increased rigidity (less fluidity), as shown by increased cholesterol/phospholipid, Sat/Unsat, and Sat/ MUFA ratios. These results were confirmed by DPH-TMA, NBDcholesterol, and NBD-sphingomyelin fluorescence polarization studies. By structure and organization, the perilipin-enriched LD most closely resembled the adipocyte PM. In contrast, the ADRP/TIP47-enriched LD contained a more fluid monolayer membrane, reflecting decreased polarizations and lipid order based on phospholipid fatty acid analysis. Taken together, results indicate that perilipin and associated lipolytic enzymes target areas in the phospholipid monolayer that are highly organized and rigid, similar in structure to localized areas of the PM where cholesterol and fatty acid uptake and efflux occur. lipolysis; caveolae; caveolin; concanavalin-A; adipose differentiationrelated protein IT IS INCREASINGLY CLEAR THAT LIPID DROPLETS (LD) are dynamic organelles with regulatory roles in many cellular processes besides lipid metabolism, including cell signaling, immune function, membrane trafficking, and regulation of longevity (42,70). Whereas the mechanism of these processes is only partially understood, much less is known about how the structure of the LD phospholipid monolayer may affect LD protein targeting and function. Embedded in the monolayer that surrounds the LD neutral lipid (NL) core are proteins, such as perilipins (65) and adipose differentiation-related protein (ADRP) (16,41), that coat the LD surface and lipids such as cholesterol (4, 80) that help to define the LD structure. Perilipin and ADRP are two members of the PAT [perilipin, ADRP, tail-interacting protein 47 (TIP47)] family from the Plin group of genes (56) that were initially thought to act simply as barriers to protect the NL core against lipolytic action (63, 65). Current evidence suggests a more complex mechanism, one that requires coordination of perilipin with several lipases, including adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), and the activator molecule comparative gene identification-58 (CGI-58), a protein with no lipolytic activity that increases ATGL activity to promote triacylglyerol hydrolysis (11,14,44). Perilipin and HSL upon hormonal stimu...

show abstract

Section: Discussionmentioning

confidence: 62%

The phospholipid monolayer associated with perilipin-enriched lipid droplets is a highly organized rigid membrane structure

Storey¹,

McIntosh²,

Senthivinayagam

et al. 2011

American Journal of Physiology-Endocrinology and Metabolism

View full text Add to dashboard Cite

show abstract

“…We found that the decrease in Na-Pi cotransport activity as a function of cholesterol enrichment is paralleled by a similar decrease in BBM fluidity. In the present study we did not measure the effects ofcholesterol enrichment on the static and dynamic components of membrane fluidity separately, however, previous studies in artificial liposomes and biological membranes have indicated that in lipid bilayers with a low cholesterol to phospholipid (< 0.33) and/or saturated to unsaturated fatty acid molar ratio, cholesterol enrichment has a more pronounced effect on the static component of fluidity, whereas in lipid bilayers with a high cholesterol to phospholipid (> 0.40) and/or saturated to unsaturated fatty acid molar ratio, such as the renal BBM, cholesterol enrichment has similar effects on both the static as well as the dynamic components of membrane fluidity (33)(34)(35).…”

Section: Discussionmentioning

confidence: 99%

Cholesterol modulates rat renal brush border membrane phosphate transport.

Levi¹,

Baird²,

Wilson³

1990

J. Clin. Invest.

View full text Add to dashboard Cite

In dietary phosphate (Pi) deprivation and in aging there is an inverse correlation between renal proximal tubular brush border membrane (BBM) cholesterol (Chol) content, BBM fluidity, and BBM sodium gradient-dependent Pi transport activity (Na-Pi cotransport). The purpose of this study was to determine whether in vitro enrichment of renal BBM with Chol has a direct modulating effect on Na-Pi cotransport. 12 and 24 mol % increases in Chol content caused dose-dependent decreases in Na-Pi cotransport activity, 2,000 in control, vs. 1,450 in Chol (+12%), vs. 900 pmol/5 s/mg BBM protein in Chol (+24%), all P < 0.01, which was paralleled by dose-dependent increases in the fluorescence anisotropy of diphenylhexatriene, rDpH, i.e., decrease in BBM fluidity, 0.203 in control, vs. 0.210 in Chol (+12%), vs. 0.219 in Chol (+24%), all P < 0.01. We found that increasing ambient temperature, which increases BBM fluidity independent of changes in Chol content, increased Na-Pi cotransport. When Na-Pi cotransport was analyzed as a function of BBM fluidity, l/rDpH, we found that at an equivalent BBM fluidity BBM Chol enrichment still resulted in a dose-dependent decrease in Na-Pi cotransport. Finally, in BBM isolated from rats fed a low Pi diet in vitro enrichment with Chol completely reversed the adaptive increases in Na-Pi cotransport and fluidity. Our study therefore, indicates that Chol is a direct modulator of renal BBM Na-Pi cotransport activity, and that in vivo alterations in BBM Chol content most likely plays an important role in the regulation of renal tubular Pi transport. (J. Clin. Invest. 1990.85:231-237.) acid binding -brush border membrane * cholesterol * fluidityNa-Pi cotransport-phosphonoformic

show abstract

“…Multilamellar liposomes of 16:0/18:1-, 18:0/18:1-, 16:0/20:4, and 18:0/20:4-PC were prepared in 20 mM sodium phosphate pH 7.1 using the procedure described by Kutchai et al (24). For labeling with DPH, 2 mL of a 2.5 µM probe dispersion in 20 mM phosphate buffer pH 7.1 were mixed with the same volume of liposome preparations, agitated, and incubated at 40°C for 30 min.…”

Section: Methodsmentioning

confidence: 99%

Molecular species of phosphoglycerides in liver microsomes of rats fed a fat‐free diet

Garda¹,

Bernasconi²,

Tricerri³

et al. 1997

Lipids

View full text Add to dashboard Cite

The influence of a fat-free diet on the molecular species composition of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositol (PI) of rat liver microsomes was studied by using reversed-phase high-pressure liquid chromatography. In the three phosphoglyceride classes analyzed, the fat-free diet produced a large decrease in the 18:0/20:4n-6 species but less important changes were found in the 16:0/20:4n-6 species. In PC, the most abundant phosphoglyceride class of rat liver microsomes, the fall in the 18:0/20:4n-6 species was counterbalanced mainly by an enhancement in the 16:0/18:1n-9 species although it was not evident in PE. In PI, the decrease in the 18:0/20:4n-6 species was counterbalanced by an increase in the 18:0/20:3n-9 species. Fluorescence polarization measurements of 1,7-diphenyl-1,3,5-hexatriene in liposomes of 16:0/18:1n-9, 18:0/18:1n-9-, 16:0/20:4n-6-, and 18:0/20:4n-6-PC indicated that the change in the saturated fatty acid in the sn-1 position accompanying the replacement of 20:4n-6 by 18:1n-9 could be very important for a homeoviscous compensation, maintaining the membrane physical properties without large alterations in spite of the essential fatty acid deficiency due to the fat-free diet.

show abstract

Effects of cholesterol on acyl chain dynamics in multilamellar vesicles of various phosphatidylcholines

Cited by 65 publications

References 34 publications

The phospholipid monolayer associated with perilipin-enriched lipid droplets is a highly organized rigid membrane structure

The phospholipid monolayer associated with perilipin-enriched lipid droplets is a highly organized rigid membrane structure

Cholesterol modulates rat renal brush border membrane phosphate transport.

Molecular species of phosphoglycerides in liver microsomes of rats fed a fat‐free diet

Contact Info

Product

Resources

About