|
|
||||||||
Correspondence to:
Robert O. Ryan
Apolipophorin III (apoLp-III) from Locusta migratoria is an exchangeable apolipoprotein that binds reversibly to lipoprotein surfaces. The native protein is glycosylated at Asn-18 and Asn-85. Variable attachment of five distinct oligosaccharide moieties at the two glycosylation sites results in molecular weight heterogeneity, as seen by mass spectrometry. The main mass peak of 20,488 Da decreases to 17,583 Da after removal of carbohydrate, indicating that apoLp-III carbohydrate mass is ~14% by weight. Deglycosylated apoLp-III induced clearance of dimyristoylphosphatidylcholine and dimyristoylphosphatidylglycerol vesicles at a faster rate than glycosylated apoLp-III. However, in lipoprotein binding assays, in which apoLp-III interacts with surface-localized diacylglycerol, only minor differences in binding were observed. The fluorescence properties of 1-anilinonaphthalene-8-sulfonate were unaffected by the glycosylation state of apoLp-III, indicating that no changes in the relative amount of exposed hydrophobic surface occurred as a result of carbohydrate removal.
We propose that glycosyl moieties affect the ability of apoLp-III to transform phospholipid bilayer vesicles into disc-like complexes by steric hindrance. This is due to the requirement that apoLp-III penetrate the bilayer substrate prior to conformational opening of the helix bundle. On the other hand, the glycosyl moieties do not affect lipoprotein binding interactions as it does not involve deep protein penetration into the lipid milieu. Rather, lipoprotein binding is based on oriented protein contact with the lipid surface followed by opening of the helix bundle, which allows formation of a stable interaction with surface exposed hydrophobic sites.Weers, P. M. M., D. J. Van der Horst, and R. O. Ryan. Interaction of locust apolipophorin III with lipoproteins and phospholipid vesicles: effect of glycosylation. J. Lipid Res. 2000. 41: 416;423.
Supplementary key words:
exchangeable apolipoproteins, lipid protein interactions, lipophorin, apoLp-III, locust
Copyright © 2000 by Lipid Research, Inc.
Original Article
Interaction of locust apolipophorin III with lipoproteins and phospholipid vesicles: effect of glycosylation
Paul M. M. Weersa,
Dick J. Van der Horstb, and
Robert O. Ryana
a Lipid and Lipoprotein Research Group, Department of Biochemistry, University of Alberta, Edmonton, T6G 2S2 Canada
b Biochemical Physiology Research Group, Faculty of Biology and Institute of Biomembranes, Utrecht University, Utrecht, The Netherlands
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
This article has been cited by other articles:
![]() |
J. A. Beckstead, K. Wong, V. Gupta, C.-P. L. Wan, V. R. Cook, R. B. Weinberg, P. M. M. Weers, and R. O. Ryan The C Terminus of Apolipoprotein A-V Modulates Lipid-binding Activity J. Biol. Chem., May 25, 2007; 282(21): 15484 - 15489. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. S. Kiss, P. M. M. Weers, V. Narayanaswami, J. Cohen, C. M. Kay, and R. O. Ryan Structure-guided Protein Engineering Modulates Helix Bundle Exchangeable Apolipoprotein Properties J. Biol. Chem., June 6, 2003; 278(24): 21952 - 21959. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. L. Segall, P. Dhanasekaran, F. Baldwin, G. M. Anantharamaiah, K. H. Weisgraber, M. C. Phillips, and S. Lund-Katz Influence of apoE domain structure and polymorphism on the kinetics of phospholipid vesicle solubilization J. Lipid Res., October 1, 2002; 43(10): 1688 - 1700. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Soulages, E. L. Arrese, P. S. Chetty, and V. Rodriguez Essential Role of the Conformational Flexibility of Helices 1 and 5 on the Lipid Binding Activity of Apolipophorin-III J. Biol. Chem., August 31, 2001; 276(36): 34162 - 34166. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Journal of Biological Chemistry |
| Molecular and Cellular Proteomics | ASBMB Today |