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This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Muszbek, L. Articles by Laposata, M. Search for Related Content PubMed PubMed Citation Articles by Muszbek, L. Articles by Laposata, M. Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  Covalent modification of platelet proteins by palmitate L Muszbek and M Laposata Department of Pathology and Laboratory Medicine, University of Pennsylvania, School of Medicine, Philadelphia 19104. Covalent attachment of fatty acid to proteins plays an important role in association of certain proteins with hydrophobic membrane structures. In platelets, the structure of many membrane glycoproteins (GPs) has been examined in detail, but the question of fatty acid acylation of platelet proteins has not been addressed. In this study, we wished to determine (a) whether platelet proteins could be fatty acid acylated; and, if so, (b) whether these modified proteins were present in isolated platelet membranes and cytoskeletal fractions; and (c) if the pattern of fatty acid acylated proteins changed on stimulation of the platelets with the agonist thrombin. We observed that in platelets allowed to incorporate 3H-palmitate, a small percentage (1.37%) of radioactivity incorporated into the cells became covalently bound to protein. Selective cleavage of thioester, thioester plus O-ester, and amide-linked 3H-fatty acids from proteins, and their subsequent analysis by high-performance liquid chromatography (HPLC) indicated that the greatest part of 3H-fatty acid covalently bound to protein was thioester-linked 3H-palmitate. By sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography, at least ten major radiolabeled proteins were detected. Activation of platelets by thrombin greatly increased the quantity of 3H- palmitoylated proteins associated with the cytoskeleton. Nearly all radiolabeled proteins were recovered in the membrane fraction, indicating that these proteins are either integral or peripheral membrane proteins or proteins tightly associated to membrane constituents. Components of the GPIIb-IIIa complex were not palmitoylated. Thus, platelet proteins are significantly modified posttranslationally by 3H-palmitate, and incorporation of palmitoylated proteins into the cytoskeleton is a prominent component of the platelet response to thrombin stimulation. Volume 74, Issue 4, pp. 1339-1347, 09/01/1989 Copyright © 1989 by The American Society of Hematology CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this? This article has been cited by other articles: S. M. Innis and R. A. Dyer Dietary Canola Oil Alters Hematological Indices and Blood Lipids in Neonatal Piglets Fed Formula J. Nutr., July 1, 1999; 129(7): 1261 - 1268. [Abstract] [Full Text]

	Copyright © 1989 by American Society of Hematology         Online ISSN: 1528-0020