Binding Preferences for GPIHBP1, a Glycosylphosphatidylinositol-Anchored Protein of Capillary Endothelial Cells

作者：Gin Peter; Beigneux Anne P; Voss Constance; Davies Brandon S J; Beckstead Jennifer A; Ryan Robert O; Bensadoun Andre; Fong Loren G; Young Stephen G^*

来源：Arteriosclerosis, Thrombosis, and Vascular Biology, 2011, 31(1): 176-+.

DOI：10.1161/ATVBAHA.110.214718

• apolipoproteins
• lipids
• lipoproteins
• metabolism

Objective-To define the ability of GPIHBP1 to bind other lipase family members and other apolipoproteins (apos) and lipoproteins.
Methods and Results-GPIHBP1, a GPI-anchored lymphocyte antigen (Ly) 6 protein of capillary endothelial cells, binds lipoprotein lipase (LPL) avidly, but its ability to bind related lipase family members has never been evaluated. As judged by cell-based and cell-free binding assays, LPL binds to GPIHBP1, but other members of the lipase family do not. We also examined the binding of apoAV-phospholipid disks to GPIHBP1. ApoAV binds avidly to GPIHBP1-transfected cells; this binding requires GPIHBP1's amino-terminal acidic domain and is independent of its cysteine-rich Ly6 domain (the latter domain is essential for LPL binding). GPIHBP1-transfected cells did not bind high-density lipoprotein. Chylomicrons bind avidly to GPIHBP1-transfected Chinese hamster ovary cells, but this binding is dependent on GPIHBP1's ability to bind LPL within the cell culture medium.
Conclusion-GPIHBP1 binds LPL but does not bind other lipase family members. GPIHBP1 binds apoAV but does not bind apoAI or high-density lipoprotein. The ability of GPIHBP1-transfected Chinese hamster ovary cells to bind chylomicrons is mediated by LPL; chylomicron binding does not occur unless GPIHBP1 first captures LPL from the cell culture medium. (Arterioscler Thromb Vasc Biol. 2011;31:176-182.)

• 出版日期2011-1