J. Lipid Res.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Originally published In Press as doi:10.1194/jlr.M800167-JLR200 on June 27, 2008

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
M800167-JLR200v1
49/10/2161    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Google Scholar
Right arrow Articles by Kuksis, A.
Right arrow Articles by Pruzanski, W.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kuksis, A.
Right arrow Articles by Pruzanski, W.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Journal of Lipid Research, Vol. 49, 2161-2168, October 2008
Copyright © 2008 by American Society for Biochemistry and Molecular Biology

Phase composition of lipoprotein SM/cholesterol/PtdCho affects FA specificity of sPLA2s

Arnis Kuksis1,* and Waldemar Pruzanski{dagger}

* Banting and Best Department of Medical Research, University of Toronto, Toronto, ON M5G 1L6, Canada
{dagger} Department of Medicine, University of Toronto, Toronto, ON M5G 1L6, Canada

This work was supported in part by grants-in-aid from the Heart and Stroke Foundation of Ontario, Canada.

Published, JLR Papers in Press, June 27, 2008.

1 To whom correspondence should be addressed. e-mail: arnis.kuksis{at}utoronto.ca

We have previously reported preferential release of polyunsaturated FAs during hydrolysis of lipoprotein phosphatidylcholine (PtdCho) by group X secretory phospholipase A2 (sPLA2) and preferential release of oligounsaturated FAs during hydrolysis of lipoprotein PtdCho by group V sPLA2, but the mechanism of this selectivity has remained unknown. We now show that the rate and specificity of hydrolysis are affected by relative increases in endogenous SM and free cholesterol (FC) during the lipase digestion. The highest preference for arachidonate release from LDL and HDL by group X sPLA2 was observed for residual SM/PtdCho molar ratio of 1.2 and 0.4, compared with the respective starting ratios of 0.4 and 0.2, as measured by liquid chromatography/electrospray ionization-mass spectrometry. Group V sPLA2 showed preferential release of linoleate from LDL and HDL at SM/PtdCho ratio 1.5 and 0.6, respectively. We have attributed the change in FA specificity to segregation of molecular species of PtdCho and of sPLA2s between disordered and ordered SM/FC/PtdCho lipid phases. The increases in SM and FC during digestion with group IIA sPLA2 were more limited, and a preferential hydrolysis of any FAs was not observed. The significance of SM and FC SM and FC accumulation during sPLA2 hydrolysis of lipoprotein PtdCho has been previously overlooked.

Supplementary key words secretory phospholipase A2 • phosphatidylcholine • sphingomyelin • phase diagrams • liquid chromatography-mass spectrometry

Abbreviations: ESI, electrospray ionization; FC, free cholesterol; GroPCho, glycerophosphocholine; LC, liquid chromatography; MS, mass spectrometry; PtdCho, phosphatidylcholine; PtdEtn, phosphatidylethanolamine; PtdSer, phosphatidylserine; sPLA2, secretory phospholipase A2


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 All ASBMB Journals   Journal of Biological Chemistry 
 Molecular and Cellular Proteomics   ASBMB Today 
Copyright © 2008 by the American Society for Biochemistry and Molecular Biology.