1. Repository of OAI
  2. ΑΠΟΘΕΤΗΡΙΟ "ΟΛΥΜΠΙΑΣ"
  3. Σχολή Θετικών Επιστημών
  4. Τμήμα Χημείας
  5. Άρθρα σε επιστημονικά περιοδικά ( Ανοικτά). ΧΗΜ
Ελληνικά   English  
Please use this identifier to cite or link to this item: https://olympias.lib.uoi.gr/jspui/handle/123456789/8871
Full metadata record
DC FieldValueLanguage
dc.contributor.authorTsoukatos, D. C.en
dc.contributor.authorLiapikos, T. A.en
dc.contributor.authorTselepis, A. D.en
dc.contributor.authorChapman, M. J.en
dc.contributor.authorNinio, E.en
dc.date.accessioned2015-11-24T16:45:02Z-
dc.date.available2015-11-24T16:45:02Z-
dc.identifier.issn0264-6021-
dc.identifier.urihttps://olympias.lib.uoi.gr/jspui/handle/123456789/8871-
dc.rightsDefault Licence-
dc.subjectatherosclerosisen
dc.subjectinflammationen
dc.subjectlipoprotein subfractionsen
dc.subjectoxidized ldlen
dc.subjectlecithin-cholesterol acyltransferaseen
dc.subjectpaf-degrading acetylhydrolaseen
dc.subjectphospholipase a(2)en
dc.subjectcoronary hearten
dc.subjectoxidationen
dc.subjectldlen
dc.subjecthydrolysisen
dc.subject1-acyl-2-acetyl-sn-glycero-3-phosphocholineen
dc.subjectaggregationen
dc.subjectinhibitoren
dc.titlePlatelet-activating factor acetylhydrolase and transacetylase activities in human plasma low-density lipoproteinen
heal.typejournalArticle-
heal.type.enJournal articleen
heal.type.elΆρθρο Περιοδικούel
heal.identifier.secondary<Go to ISI>://000170112500014-
heal.languageen-
heal.accesscampus-
heal.recordProviderΠανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείαςel
heal.publicationDate2001-
heal.abstractIn this study, we demonstrate the presence of a transacetylase activity in human plasma low-density lipoprotein (LDL) that transfers short-chain fatty acids from platelet-activating factor (PAF) and its close ether- and ester-linked analogues to ether/ester-linked lysophospholipids (lyso-PL). We show evidence that both PAF acetylhydrolase (PAF-AH) and transacetylase activities are inhibited to the same extent by serine esterase inhibitors, are resistant to heat treatment, and exhibit identical distributions in lipoprotein classes and in LDL subfractions. Additionally, the competitive inhibition of PAF-AH by lyso-PL, and the evidence that the recombinant PAF-AH also showed a similar transacetylase activity, suggest that PAF-AH is responsible for both activities. Using PAF as a donor molecule and lyso-PAF (1-O-alkyl-sn-glycero-3-phosphocholine) as an acceptor, the transacetylase activity showed typical allosteric kinetics, due to the positive co-operativity of the substrates, with apparent V-max = 19.6 +/- 3.4 nmol/min per mg of protein, apparent h = 2.0 +/- 0.3 and apparent [S](0.5) = 9.4 +/- 2.3 muM at saturation for the concentration of lyso-PAF. The substrate specificity of the donor molecules was decreased by increasing the chain length of the acyl moiety in the sn-2 position of the glycerol. The ether linkage in the sn-1 position of the substrate was 30% more effective than the ester bond; cholesteryl acetate was inactive as an acetyl donor. The two acceptors tested, lyso-PAF and the ester-linked lyso-PC (1-acyl-sn-glycero-3-phosphocholine), showed similar specificity. Addition of exogenous lyso-PAF induced the transient formation of PAF-like aggregating activity predominately in small dense LDL subfractions upon oxidation. We conclude that PAF-AH possesses both transacetylase and acetylhydrolase activities which remove PAF and its ether-linked analogues from LDL particles upon LDL oxidation. However, in atherogenic small dense LDL-5 particles, the transacetylase activity may acetylate extracellular lyso-PAF into biologically active PAF.en
heal.journalNameBiochemical Journalen
heal.journalTypepeer reviewed-
heal.fullTextAvailabilityTRUE-
Appears in Collections:Άρθρα σε επιστημονικά περιοδικά ( Ανοικτά). ΧΗΜ

Show simple item record
Files in This Item:
There are no files associated with this item.
Show simple item record  


This item is licensed under a Creative Commons License Creative Commons