Transfer of phospholipids between membrane

Wirtz, K.W.A.

doi:10.1016/0304-4157(74)90001-x

Cited by 310 publications

(61 citation statements)

References 118 publications

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“…This is in agreement with immunological studies on levels of PC-transfer protein in bovine tissues [6]. It is of interest to note that the 105000 X g supernatant from rat brain does not have any phosphatidylethanolamine-transfer activity [37]. This implies that rat brain lacks the non-specific phospholipid-transfer protein which presumably is responsible for this activity [7].…”

Section: Discussionsupporting

confidence: 84%

“…PC-transfer protein is thought to be involved in the intracellular transport of phosphatidylcholine from the site of synthesis, i.e., the endoplasmic reticulum, to those sites where phosphatidylcholine is required [37]. In this respect it is worth noting that of all tissues examined the highest levels of PC-transfer protein are present in liver and intestinal mucosa.…”

Section: Discussionmentioning

confidence: 99%

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Tissue distribution and subcellular localization of phosphatidylcholine transfer protein in rats as determined by radioimmunoassay

Teerlink

Krift

Post

et al. 1982

Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metaboli

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A radioimmunoassay for the phosphatidylcholine-transfer protein from rat liver was used to measure levels of PC-transfer protein in rat tissues. The assay as described before (Tee&k, T., Poorthuis, B.J.H.M., Van der Krift, T.P. and Wirtz, K.W.A., Biochim. Biophys. Acta 665 (1981) 74-80) was modified in order to measure PC-transfer protein in tissue homogenates and subcellular membrane fractions. To this end both a detergent (Triton X-100) and a proteolytic enzyme inhibitor (aprotinin) were added to the assay medium. The radioimmunoassay measured levels of PC-transfer protein in the range of 5-50 ng and was specific for PC-transfer protein from rat tissues. Subcellular distribution studies showed that in 10% (w/v) homogenates of liver approximately 60% of the PC-transfer protein was present in the 105000X g supernatant fraction, the remainder being evenly distributed over the particulate fractions. PC-transfer protein associated with the particulate fractions was almost completely removed by a single washing step, suggesting a dynamic equilibrium between membrane-bound and soluble PC-transfer protein. Both 105000X g supematants and homogenates of various rat tissues were assayed. The highest levels of PC-transfer protein were measured in liver and intestinal mucosa. Lower values were found in kidney, spleen and lung, whereas heart and brain contained hardly any PC-transfer protein. PC-transfer protein levels in regenerating rat liver did not differ significantly from levels in normal liver. In fetal lung a change in PC-transfer protein content during development was observed, with a clear maximum 2 days before term, suggesting an involvement of PC-transfer protein in the secretion of lung surfactant.

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Section: Discussionsupporting

confidence: 84%

Section: Discussionmentioning

confidence: 99%

Tissue distribution and subcellular localization of phosphatidylcholine transfer protein in rats as determined by radioimmunoassay

Teerlink

Krift

Post

et al. 1982

Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metaboli

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“…An antiserum against this protein was raised in rabbits. Treatment of a rat liver supernatant fraction with the antiserum immunoglobulin fraction demonstrated that 60 % of the phosphatidylcholine transfer activity is due to this protein.The transfer of phospholipids between membranes has been shown to be stimulated by proteins in the 105000xg supernatant of a variety of cells [1,2]. It has been suggested that these proteins play a role in determining the phospholipid composition of eucaryotic cell membranes [3], in membrane biogenesis [2] and possibly in synaptic transmission of nerve impulses [4].…”

mentioning

confidence: 99%

Some Properties of Phospholipid Exchange Proteins from Rat Liver

Lumb

Kloosterman

Wirtz

et al. 1976

European Journal of Biochemistry

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The phospholipid exchange proteins of rat liver that catalyze the transfer of phosphatidylcholine and phosphatidylinositol from rat liver microsomes to liposomes, have been purified and characterized.Two proteins were detected with dual specificities catalyzing the transfer of both phosphatidylinositol and phosphatidylcholine. Both proteins showed a strong preference for phosphatidylinositol transferring 8 to 9 times as much of the microsomal phosphatidylinositol pool as the microsomal phosphatidylcholine pool. The two proteins had iso-electric points of 5.1 and 5.3 and were purified 300-fold and 500-fold, respectively.A protein that catalyzed specifically the transfer of phosphatidylcholine, was purified 7000-fold. This protein had an iso-electric point of 8.4 and a molecular weight of approximately 16 000 calculated from Sephadex G-50 chromatography and sodium dodecylsulfate-polyacrylamide gel electrophoresis ; the amino acid composition was determined. An antiserum against this protein was raised in rabbits. Treatment of a rat liver supernatant fraction with the antiserum immunoglobulin fraction demonstrated that 60 % of the phosphatidylcholine transfer activity is due to this protein.The transfer of phospholipids between membranes has been shown to be stimulated by proteins in the 105000xg supernatant of a variety of cells [1,2]. It has been suggested that these proteins play a role in determining the phospholipid composition of eucaryotic cell membranes [3], in membrane biogenesis [2] and possibly in synaptic transmission of nerve impulses [4]. Phospholipid exchange proteins may thus be important to many membrane-associated functions.The transfer of phosphatidylcholine, phosphatidylinositol and phosphatidylethanolamine between membranes has been demonstrated with rat liver [5 -101 and bovine liver supernatant [l 11. Recent studies have indicated that bovine brain and liver supernatant contain one exchange protein specific for phosphatidylcholine, and two exchange proteins both of which transfer phosphatidylinositol and, to a lesser extent, phosphatidylcholine [12]. All three proteins are acidic with iso-electric points between 5 and 6. In the present study we have further characterized the phosphatidylinositol and phosphatidylcholine exchange proteins in rat liver.Here we report the presence of an exchange protein in rat liver with an iso-electric point of 8.4 that transfers specifically phosphatidylcholine. In addition two proteins have been partially characterized with isoelectric points of 5.1 and 5.3 and transfer activities towards both phosphatidylinositol and phosphatidylcholine. While this work was in progress a report appeared showing phosphatidylcholine transfer activity in rat intestinal supernatant [13]. On iso-electric focusing this activity concentrated at both acidic (4.5-5.3) and basic (8-9) iso-electric points. MATERIALS AND METHODS Purgication of Phosphatidylinositol and Phosphatidylcholine Exchange ProteinsLivers were obtained from Wistar rats and stored at -20 "C until used. Prior to use ...

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“…Our hypothesis is that in vivo these proteins act as carriers of phospholipids between the endoplasmic reticulum and membranes not capable of de novo phospholipid synthesis, for example, mitochondria [6]. Membrane alterations in phospholipid content and composition could possibly be related to "changes in levels and relative distribution of phospholipid exchange proteins.…”

Section: Discussionmentioning

confidence: 96%

“…Proteins present in the cytosol fraction of tissue homogenates and capable of catalyzing transfer of phospholipids in vitxo have been implicated in the intracellular transport of phospholipids from their site of synthesis to membranes not capable of de novo lipid synthesis [6]. As yet, no direct proof for such a role is available, although there is indirect evidence suggesting a link between phospholipid exchange activities and phospholipid biosynthesis in developing mouse lung [7] and in rat brain [8].…”

Section: Introductionmentioning

confidence: 99%

Phospholipid transfer activities in morris hepatomas and the specific contribution of the phosphatidylcholine exchange protein

Poorthuis

Krift

Teerlink

et al. 1980

Biochimica et Biophysica Acta (BBA) - Biomembranes

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SummaryPhospholipid transfer activities for phosphatidylcholine, phosphatidylinositol and phosphatidylethanolamine were measured in three hepatomas of increasing growth rate and degree of dedifferentiation, the hepatomas 7787, 9633 and 7777, and compared to the activities found in normal and host liver. A 2--3-fold increase was found in the phosphatidylcholine and phosphatidyinositol transfer activities in the fast-growing 7777 hepatoma, while these activities were moderately or not increased in the 7787 and 9633 hepatomas. Phosphatidylethanolamine transfer was found to be extremely low in all three hepatomas. The possible significance of these findings with respect to the altered phospholipid content and composition of the hepatoma membranes is discussed.The contribution of the phosphatidylcholine specific exchange protein to the total phosphatidylcholine transfer activity was determined in normal and host liver and in the hepatomas 7777 and 9633 with the aid of a phosphatidylcholine exchange protein specific antiserum. To this end a new procedure for the purification of the phosphatidylcholine exchange protein from mt liver was developed which leads to a final purification factor of 5300 and a high overall yield of 17%. In addition, this protein was chemically and immunologically characterized and its properties were compared to those of the bovine phosphatidylcholine exchange protein purified in our laboratory previously.

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Transfer of phospholipids between membrane

Cited by 310 publications

References 118 publications

Tissue distribution and subcellular localization of phosphatidylcholine transfer protein in rats as determined by radioimmunoassay

Tissue distribution and subcellular localization of phosphatidylcholine transfer protein in rats as determined by radioimmunoassay

Some Properties of Phospholipid Exchange Proteins from Rat Liver

Phospholipid transfer activities in morris hepatomas and the specific contribution of the phosphatidylcholine exchange protein

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