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A novel "salting-out" procedure for the isolation of tumor-derived exosomes. J Immunol Methods 2014; 407:120-6. [PMID: 24735771 DOI: 10.1016/j.jim.2014.04.003] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 03/02/2014] [Accepted: 04/04/2014] [Indexed: 12/17/2022]
Abstract
The last decade has seen an exponential growth in the number of exosome-related publications. Although many of these studies have used exosomes from biological fluids (blood, and ascites or pleural effusions) the vast majority employed vesicles isolated from large volumes of tissue culture supernatants. While several techniques are available for their isolation, all require a significant reduction in volume to obtain sufficient concentrations for study. One approach is to concentrate the medium before proceeding with their isolation, however, these procedures are very time consuming and require specialized laboratory equipment. Here we provide a new and effective method for the isolation of tumor-derived exosomes based on "charge neutralization" with acetate. We show that titration of tissue culture supernatants with 0.1M acetate to pH4.75 results in immediate precipitation of virtually all the exosomes. The precipitated exosomes can be washed to remove residual media and are readily "resolubilized" upon resuspension in acetate-free buffer at neutral pH. This simple cost effective method significantly increases the yield of exosomes from an unlimited quantity of culture supernatants. Exosomes isolated by this technique are indistinguishable from exosomes recovered by direct ultracentrifugation.
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Marmé D, Boisard J, Briggs WR. Binding properties in vitro of phytochrome to a membrane fraction. Proc Natl Acad Sci U S A 2010; 70:3861-5. [PMID: 16592127 PMCID: PMC427345 DOI: 10.1073/pnas.70.12.3861] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Brief irradiation of a buffer extract of dark-grown zucchini squash seedlings with red light results in the binding of the far-red-absorbing form of phytochrome to a particulate fraction. A low concentration of magnesium (0.1 mM) permits partial far-red reversal of the binding. A higher concentration (10 mM) yields actually enhanced binding after the far-red treatment. Both magnesium and calcium have a strong effect on the vesicularization of the phytochrome-binding particles and on their aggregation into readily sedimentable complexes. At concentrations above 10 mM, binding of the far-red-absorbing form of phytochrome is inhibited. These effects were not observed with sodium or potassium. Increasing the H(+) concentration led to increased binding of the far-red-absorbing form. This form of phytochrome bound at pH 6.5 and 10 mM magnesium is released if either the pH is raised to 8.0 or the magnesium concentration is raised to 50 mM. These properties suggest a new method for phytochrome purification.
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Affiliation(s)
- D Marmé
- The Biological Laboratories, Harvard University, Cambridge, Massachusetts 02138
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Chapman D. Protein-lipid interactions. CIBA FOUNDATION SYMPOSIUM 2008; 7:261-88. [PMID: 4592575 DOI: 10.1002/9780470719909.ch15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Aguilar JS, de Cózar M, Criado M, Monreal J. The delipidation of brain proteolipid protein by ultrafiltration. J Neurochem 1983; 40:585-8. [PMID: 6822841 DOI: 10.1111/j.1471-4159.1983.tb11323.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
It has been very difficult to prepare the apoprotein moiety of brain white matter proteolipid so that it is completely devoid of complex lipids, without suffering aggregation and protein denaturation. The reason is that complex lipids are tightly bound to the proteolipid apoprotein. Using a new ultrafiltration method, we obtained, in a gradual way and in a relatively short time, more than 99% delipidation in water-saturated n-butanol, with and without 0.1 M acetic acid, and recovered up to 86% of the protein with no detectable reducing sugars remaining. The delipidated protein remained in solution and in a relatively nondenatured state for several days. In 2% sodium dodecyl sulfate (SDS)-aqueous media, 90% of the lipids were removed and the yield of recovered protein in solution was near 90%; nearly 6% of the reducing sugars remained in the apoprotein. A higher delipidation was obtained by washing with 0.1 M NaOH. The content of reducing sugars was greater but the protein was less stable. When 10% SDS was employed to dissociate lipid-protein interaction, an almost complete delipidation was obtained and reducing sugars disappeared.
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Zwaal RF. Membrane and lipid involvement in blood coagulation. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 515:163-205. [PMID: 356885 DOI: 10.1016/0304-4157(78)90003-5] [Citation(s) in RCA: 179] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Barzilay M, de Vries A, Condrea E. Recombination of integral and peripheral protein fractions from human red cell membrane with homologous lipids. EXPERIENTIA 1977; 33:1102-5. [PMID: 891828 DOI: 10.1007/bf01945996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Integral and peripheral protein fractions from human red cells membranes were recombined with a total red cell lipid extract and with homologous lipids in varying mixtures, by dialysis from 2-chlorethanol solutions. The 2 protein fractions were compared for lipid binding capacity and for selectivity towards individual lipids.
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Wehrli E, Moser S, Zahler P. Effects of pH during recombination of human erythrocyte membrane apoprotein and lipid. BIOCHIMICA ET BIOPHYSICA ACTA 1976; 426:271-87. [PMID: 3225 DOI: 10.1016/0005-2736(76)90337-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The recombinates from human red cell membrane proteins and lipids resulting from dialysis of the components in 2-chloroethanol against aqueous buffers from pH2-12 have been studied by density gradient centrifugation, polyacrylamide gel electrophoresis and freeze-fracture electron microscopy. Between pH 4 and 10 most of the proteins were found in the recombinates whereas below pH 4 and above pH 10 only part of them were recovered in the lipoprotein band after density gradient centrifugation. At low pH, increasing incorporation of the "major glycoprotein" into the recombinates was detected by gel electrophoresis and in parallel increasing amounts of particles were found in the freeze-fracture membrane faces. The necessity of working at low pH values from pH 2-4, however, and a critical evaluation of all the data presently available leads to the conclusion that the 2-choloroethanol technique is not adequate for recombination studies tending to membrane reconsitution.
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Kimelberg HK. Protein-liposome interactions and their relevance to the structure and function of cell membranes. Mol Cell Biochem 1976; 10:171-90. [PMID: 177856 DOI: 10.1007/bf01731688] [Citation(s) in RCA: 125] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Recent studies on the interactions of soluble proteins, membrane proteins and enzymes with phospholipid model membranes are reviewed. Similarities between the properties of such systems and the behavior of biomembranes, such as alterations in the redox potential of cytochrome c after binding to membranes and effects of phospholipid fluidity on (Na+K) ATPase activity, are emphasized. The degree of correspondence between the behavior of model systems and natural membranes encourages the continuing use of model membranes in studies on protein-lipid interactions. However, some of the data on the increase of surface pressure of phospholipid monolayers by proteins and increases in the permeability of liposomes indicate that many soluble proteins also have a capability to interact hydrophobically with phospholipids. Thus a sharp distinction between both peripheral and integral membrane proteins and non-membrane proteins are not seen by these techniques. Cautious use of such studies, however, should lead to greater understanding of the molecular basis of cell membrane structure and function in normal and pathological states. Studies implicating protein-lipid interactions and (Na+K) ATPase activity in membrane alterations in disease states are also briefly discussed.
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Kamp HH, Sprengers ED, Westerman J, Wirtz KW, Van Deenen LL. Action of phospholipases on the phosphatidylcholine exchange protein from beef liver. BIOCHIMICA ET BIOPHYSICA ACTA 1975; 398:415-23. [PMID: 1174523 DOI: 10.1016/0005-2760(75)90192-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The phospholipases A2, C and D have been used to investigate the localization of phosphatidylcholine in the phosphatidylcholine exchange protein from beef liver. The rate of enzymatic hydrolysis of the protein-bound phosphatidylcholine was found to be very low. Addition of deoxycholate, isobutanol or dioxane to the native protein, under conditions where delipidation did not occur, greatly enhanced the hydrolytic action of the phospholipases. From these results it is concluded that phosphatidylcholine may be buried in the protein molecule.
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Shafer PT. The interaction of polyamino acids with lipid monolayers. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 373:425-35. [PMID: 4433585 DOI: 10.1016/0005-2736(74)90022-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Morse PD. Recombination of human erythrocyte apoprotein and lipid. I. Interaction of apoprotein and lipid at the air-water interface. JOURNAL OF SUPRAMOLECULAR STRUCTURE 1974; 2:60-70. [PMID: 4369122 DOI: 10.1002/jss.400020107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Zahler P. Association and reconstitution of membrane complexes of red blood cell membranes solubilized in acidified organic solvents. Methods Enzymol 1974; 32:468-75. [PMID: 4444533 DOI: 10.1016/0076-6879(74)32046-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Lossen O, Brennecke R, Schubert D. Electrical properties of black membranes from oxidized cholesterol and a strongly bound protein fraction of human erythrocyte membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 330:132-40. [PMID: 4777222 DOI: 10.1016/0005-2736(73)90217-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Cho KS, Proulx P. Interactions of acyl carnitines and other lysins with erythrocytes and reconstituted erythrocyte lipoproteins. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 318:50-60. [PMID: 4795779 DOI: 10.1016/0005-2736(73)90335-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Barzilay M, Condrea E, Ben-David E, De Vries A. Recombination of human red cell membrane protein fractions with homologous lipids. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 311:576-93. [PMID: 4729831 DOI: 10.1016/0005-2736(73)90131-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Brailsford JD, Bull BS. The red cell--a macromodel simulating the hypotonic-sphere isotonic-disc transformation. J Theor Biol 1973; 39:325-32. [PMID: 4728720 DOI: 10.1016/0022-5193(73)90102-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Rottem S, Hasin M, Razin S. Binding of proteins to mycoplasma membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 298:876-86. [PMID: 4354127 DOI: 10.1016/0005-2736(73)90392-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Maddy AH, Dunn MJ, Kelly PG. The characterisation of membrane proteins by centrifugation and gel electrophoresis. A comparison of proteins prepared by different methods. BIOCHIMICA ET BIOPHYSICA ACTA 1972; 288:263-76. [PMID: 4628368 DOI: 10.1016/0005-2736(72)90247-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Kramer R, Schlatter C, Zahler P. Preferential binding of sphingomyelin by membrane proteins of the sheep red cell. BIOCHIMICA ET BIOPHYSICA ACTA 1972; 282:146-56. [PMID: 5070073 DOI: 10.1016/0005-2736(72)90318-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Juliano RL, Kimelberg HK, Papahadjopoulos D. Synergistic effects of a membrane protein (spectrin) and Ca 2+ on the Na + permeability of phospholipid vesicles. BIOCHIMICA ET BIOPHYSICA ACTA 1971; 241:894-905. [PMID: 5003695 DOI: 10.1016/0005-2736(71)90017-4] [Citation(s) in RCA: 81] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Berger KU, Barratt MD, Kamat VB. Magnetic resonance studies on the components of human erythrocyte membranes. Chem Phys Lipids 1971; 6:351-63. [PMID: 4334693 DOI: 10.1016/0009-3084(71)90047-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Metcalfe JC, Metcalfe SM, Engelman DM. Structural comparisons of native and reaggregated membranes from Mycoplasma laidlawii and erythrocytes by x-ray diffraction and nuclear magnetic resonance techniques. BIOCHIMICA ET BIOPHYSICA ACTA 1971; 241:412-21. [PMID: 5159791 DOI: 10.1016/0005-2736(71)90041-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Cherry RJ, Berger KU, Chapman D. Interaction of erythrocyte apoprotein with bimolecular lipid membranes. Biochem Biophys Res Commun 1971; 44:644-52. [PMID: 5123202 DOI: 10.1016/s0006-291x(71)80132-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Kimelberg HK, Papahadjopoulos D. Phospholipid-protein interactions: Membrane permeability correlated with monolayer “penetration”. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 1971. [DOI: 10.1016/0005-2736(71)90270-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Kimelberg HK, Papahadjopoulos D. Phospholipid-protein interactions: membrane permeability correlated with monolayer "penetration". BIOCHIMICA ET BIOPHYSICA ACTA 1971; 233:805-9. [PMID: 5165439 DOI: 10.1016/0005-2736(71)90181-7] [Citation(s) in RCA: 160] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Kamat VB, Chapman D, Zwaal RF, van Deenen LL. Proton magnetic resonance (PMR) spectra of erythrocyte membrane lipoproteins and apoproteins. Chem Phys Lipids 1970; 4:323-31. [PMID: 5507521 DOI: 10.1016/0009-3084(70)90032-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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