PAF

Live forum: /viewtopic.php?t=20070

Dominique

11-01-2010 19:40:20

Zit PAF nu in vesikeltjes of niet?
Want op de notitie hebben we dat wel in een cirkeltje getekend, maar in de tekst staat niet specifiek dat dat in vesikeltjes zit.

Internet ==> zou doen vermoeden dat er een bestaan is van lipide vesikeltjes met PAF in, maar dat het ook als monomeer bestaat in het plasma.

Iemand de oplossing?

Alex!

11-01-2010 22:11:04

Zit PAF nu in vesikeltjes of niet?
Want op de notitie hebben we dat wel in een cirkeltje getekend, maar in de tekst staat niet specifiek dat dat in vesikeltjes zit.

Internet ==> zou doen vermoeden dat er een bestaan is van lipide vesikeltjes met PAF in, maar dat het ook als monomeer bestaat in het plasma.

Iemand de oplossing?

Denk dat het in vrije vorm rondzwerft in het plasma, anders zou het nooit kunnen binden aan de bijbehorende receptor, tenzij natuurlijk het ingecorporeerd zou zijn in de plasmamembraan van het vesikel.

edit: Platelet-activating factor receptor.

Ishii S, Nagase T, Shimizu T.

Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Japan. mame@m.u-tokyo.ac.jp

Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a biologically active phospholipid mediator.
En dus incorporatie in een vesikel?

Dominique

11-01-2010 22:18:21

Abstract Platelet aggregation activity due to platelet-activating factor (PAF) was detected at high molecular weight (HMW) and low molecular weight fractions after gel-filtration chromatography of cell lysate of endothelial cells. [3H]PAF added to the cell lysate was similarly distributed after chromatography. The radioactivity associated with HMW fraction was not reduced by digesting the lysate with trypsin, suggesting that PAF was not making complexes with proteins but was included in lipid vesicles in cell lysate. Further evidence showed that an unknown specific factor(s) was needed to form these PAF-containing lipid vesicles. Radioactivity was not found in HMW fraction when [3H]PAF was mixed with cell lysate of vascular smooth muscle cells. When monomeric PAF was added to endothelial cell lysate, the specific activity of aggregation decreased to the level exerted by endogenous PAF-containing lipid vesicles due to incorporation into lipid vesicles. PAF in the form of lipid vesicles was more stable in plasma than monomeric form.

Of moeten we zo ver niet gaan?

Alex!

11-01-2010 22:20:39

Abstract Platelet aggregation activity due to platelet-activating factor (PAF) was detected at high molecular weight (HMW) and low molecular weight fractions after gel-filtration chromatography of cell lysate of endothelial cells. [3H]PAF added to the cell lysate was similarly distributed after chromatography. The radioactivity associated with HMW fraction was not reduced by digesting the lysate with trypsin, suggesting that PAF was not making complexes with proteins but was included in lipid vesicles in cell lysate. Further evidence showed that an unknown specific factor(s) was needed to form these PAF-containing lipid vesicles. Radioactivity was not found in HMW fraction when [3H]PAF was mixed with cell lysate of vascular smooth muscle cells. When monomeric PAF was added to endothelial cell lysate, the specific activity of aggregation decreased to the level exerted by endogenous PAF-containing lipid vesicles due to incorporation into lipid vesicles. PAF in the form of lipid vesicles was more stable in plasma than monomeric form.

Of moeten we zo ver niet gaan?

Proffen stimuleren "kritisch nadenken" toch? :D
Den Eggie is trots op u en mij! :goodboy:

Dominique

11-01-2010 22:34:29

:feest