Quantification of the interaction of lysolecithin with phosphatidylcholine vesicles using bovine serum albumin: Relevance to the activation of phospholipase A2

Brown, Sheila; Baker, Brian L.; Bell, John D.

doi:10.1016/0005-2760(93)90260-g

Cited by 28 publications

(26 citation statements)

References 22 publications

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“…This observation is in line with the affinity of this protein for other phospholipids containing only one long-chain fatty acid ( e.g. lysophospholipids) [23]. BY-POVPE also forms a stable complex with albumin which is detectable by fluorescence imaging after SDS gel electrophoresis (Fig.…”

Section: Resultssupporting

confidence: 78%

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Uptake and protein targeting of fluorescent oxidized phospholipids in cultured RAW 264.7 macrophages

Stemmer

Ramprecht

Zenzmaier

et al. 2012

Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biolog

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The truncated phospholipids 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC) and 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine (PGPC) are oxidation products of 1-palmitoyl-2-arachidonoyl phosphatidylcholine. Depending on concentration and the extent of modification, these compounds induce growth and death, differentiation and inflammation of vascular cells thus playing a role in the development of atherosclerosis. Here we describe the import of fluorescent POVPC and PGPC analogs into cultured RAW 264.7 macrophages and the identification of their primary protein targets. We found that the fluorescent oxidized phospholipids were rapidly taken up by the cells. The cellular target sites depended on the chemical reactivity of these compounds but not on the donor (aqueous lipid suspension, albumin or LDL). The great differences in cellular uptake of PGPC and POVPC are a direct consequence of the subtle structural differences between both molecules. The former compound (carboxyl lipid) can only physically interact with the molecules in its immediate vicinity. In contrast, the aldehydo-lipid covalently reacts with free amino groups of proteins by forming covalent Schiff bases, and thus becomes trapped in the cell surface. Despite covalent binding, POVPC is exchangeable between (lipo)proteins and cells, since imines are subject to proton-catalyzed base exchange. Protein targeting by POVPC is a selective process since only a limited subfraction of the total proteome was labeled by the fluorescent aldehydo-phospholipid. Chemically stabilized lipid–protein conjugates were identified by MS/MS. The respective proteins are involved in apoptosis, stress response, lipid metabolism and transport. The identified target proteins may be considered primary signaling platforms of the oxidized phospholipid.

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Section: Resultssupporting

confidence: 78%

“…Albumin may extract oxidized phospholipids from the particle, since it shows binding affinities for phospholipids containing only one long hydrophobic fatty acid, e.g. lysolecithin [23]. We were able to show that both carriers form stable complexes with fluorescent oxidized phospholipids also (Fig.…”

Section: Discussionmentioning

confidence: 69%

Uptake and protein targeting of fluorescent oxidized phospholipids in cultured RAW 264.7 macrophages

Stemmer

Ramprecht

Zenzmaier

et al. 2012

Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biolog

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“…After reductive stabilization (see above), a fluorescent band was detected after SDS electrophoresis, showing the same electrophoretic mobility as the unlabeled protein. BSA can noncovalently bind one molecule of lyso-PC [32]. The complex of this protein with BY-POVPC is in addition stabilized by a covalent imine bond.…”

Section: Schiff Base Formation By Aldehydophospholipidsmentioning

confidence: 99%

Protein modification by aldehydophospholipids and its functional consequences

Stemmer

Hermetter

2012

Biochimica et Biophysica Acta (BBA) - Biomembranes

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Phospholipid aldehydes represent a particular subclass of lipid oxidation products. They are chemically reactive and can form Schiff bases with proteins and aminophospholipids. As chemically bound molecular entities they modulate the functional properties of biomolecules in solution and the surface of supramolecular systems including plasma lipoproteins and cell membranes. The lipid–protein and lipid–lipid conjugates may be considered the active primary platforms that are responsible for the biological effects of aldehydophospholipids, e.g. receptor binding, cell signaling, and recognition by the immune system. Despite the fact that aldehydophospholipids are covalently associated, they are subject to exchange between nucleophiles since their imine conjugates are not stable. As a consequence, aldehydophospholipids exist in a dynamic equilibrium between different “states” depending on the lipid and protein environment. Aldehydophospholipids may also contribute to the systemic administration and activity of oxidized phospholipids by inducing release of microparticles by cells. These effects are lipid-specific. Future studies should help clarify the mechanisms and consequences of these membrane-associated effects of “phospholipid stress”. This article is part of a Special Issue entitled: Oxidized phospholipids—their properties and interactions with proteins.

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“…Several previous studies have addressed relationships between sPLA 2 activity and the physical properties of artificial membranes (6)(7)(8)(9)(12)(13)(14)(15)(58)(59)(60)(61)(62). These relationships can be segregated into two categories.…”

Section: Membrane Order and Spla 2 Activitymentioning

confidence: 99%

“…The other category comprises specific perturbations to membrane structure that improve interactions of sPLA 2 with the membrane surface and/ or access of bilayer substrate to the enzyme's active site. Examples of these perturbations include increased surface curvature, negative surface charge, and the presence of bilayer contaminants that weaken phospholipid/neighbor interactions in the membrane (6)(7)(8)(9)(10)(12)(13)(14)(58)(59)(60). Even though these two categories are not entirely independent in terms of their mutual effects on membrane behavior and hydrolytic activity, we have classified them in this way because they appear to modulate the enzyme by separate means (7,8,14,64).…”

Section: Membrane Order and Spla 2 Activitymentioning

confidence: 99%

Effects of Cholesterol on Physical Properties of Human Erythrocyte Membranes: Impact on Susceptibility to Hydrolysis by Secretory Phospholipase A2

Heiner

Gibbons

Fairbourn

et al. 2008

Biophysical Journal

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The ability of secretory phospholipase A(2) (sPLA(2)) to hydrolyze cell membranes is highly dependent on the physical properties of the membrane. The effects of cholesterol on these properties have been characterized in artificial bilayers and found to alter sPLA(2) activity significantly. It is hypothesized that the natural difference in cholesterol content between erythrocytes and leukocytes is in part responsible for their differing susceptibility to hydrolysis by sPLA(2). To test this hypothesis, defined amounts of cholesterol were removed from erythrocyte membranes using methyl-beta-cyclodextrin. Treatment of cells with methyl-beta-cyclodextrin increased the hydrolysis rate and total substrate hydrolyzed by sPLA(2). In general, this effect of cholesterol removal was more pronounced at higher temperatures. Comparison of the level of membrane order (assessed with the fluorescent probe laurdan) with hydrolysis rate revealed that sPLA(2) activity was greatly enhanced upon significant reductions in lipid order. Additional treatment of the cells with calcium ionophore further enhanced the hydrolysis rate and altered the relationship with membrane order. These data demonstrated that interactions with sPLA(2) observed in artificial bilayers apply to biological membranes. It is also proposed that the high level of cholesterol in erythrocyte membranes is a protective mechanism to guard against hydrolytic enzymes.

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Quantification of the interaction of lysolecithin with phosphatidylcholine vesicles using bovine serum albumin: Relevance to the activation of phospholipase A2

Cited by 28 publications

References 22 publications

Uptake and protein targeting of fluorescent oxidized phospholipids in cultured RAW 264.7 macrophages

Uptake and protein targeting of fluorescent oxidized phospholipids in cultured RAW 264.7 macrophages

Protein modification by aldehydophospholipids and its functional consequences

Effects of Cholesterol on Physical Properties of Human Erythrocyte Membranes: Impact on Susceptibility to Hydrolysis by Secretory Phospholipase A2

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