N-linked glycosylation of macrophage-derived PAF-AH is a major determinant of enzyme association with plasma HDL
Φόρτωση...
Ημερομηνία
Συγγραφείς
Tselepis, A. D.
Karabina, S. A. P.
Stengel, D.
Piedagnel, R.
Chapman, M. J.
Ninio, E.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Lipid Research Inc.
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Journal of Lipid Research
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
Human plasma PAF-AH (platelet-activating factor-acetylhydrolase) is a Ca2+-independent phospholipase A(2) of hematopoietic origin associated with LDL and HDL; it degrades PAF and oxidizes phospholipids. We show that human macrophages synthesize PAF-AH as a premedial Golgi precursor containing high mannose N-linked glycans. Secreted PAF-AH possesses a molecular mass of similar to 55 kDa and contains mature N-linked glycans. Secreted PAF-AH activity (90 +/- 4% of the total) bound to a wheat germ lectin column and could be eluted with N-acetylglucosamine, whereas digestion with N-acetylneuraminidase II completely abolished enzyme absorption. Tunicamycin significantly reduced cell-associated PAN-AH activity and inhibited enzyme secretion; but it did not alter the ratio of secreted to cell-associated enzyme (1.8 at 6 h and 3.1 at 24 h), suggesting that glycosylation is not essential for PAF-AH secretion. Digestion of cell-associated PAF-AH or secreted PAF-AH with peptide N-glycosidase F affected neither catalytic activity nor its resistance to proteolysis with trypsin or proteinase K, in addition, it did not affect PAF-AH association with LDL, but significantly increased its association with HDL. jlr We suggest that macrophage-derived PAF-AH contains heterogeneous asparagine-conjugated sugar chain(s) involving sialic acid, which hinders its association with HDL but does not influence the secretion, catalytic activity, or resistance of PAF-AH to proteases.
Περιγραφή
Λέξεις-κλειδιά
atherogenesis, lipoproteins, macrophages, platelet-activating-factor, low-density-lipoprotein, factor acetylhydrolase, endoplasmic-reticulum, degrading acetylhydrolase, catalytic activity, brefeldin-a, degradation, expression, relevance
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000171803100015
http://www.jlr.org/content/42/10/1645.full.pdf
http://www.jlr.org/content/42/10/1645.full.pdf
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας