Characterization of the Ligand Binding Activities of Vitronectin: Interaction of Vitronectin with Lipids and Identification of the Binding Domains for Various Ligands Using Recombinant Domains
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- 作者：Atsuko Yoneda ; Haruko Ogawa ; Kyoko Kojima ; and Isamu Matsumoto
- 刊名：Biochemistry
- 出版年：1998
- 出版时间：May 5, 1998
- 年：1998
- 卷：37
- 期：18
- 页码：6351 - 6360
- 全文大小：139K
- 年卷期：v.37,no.18(May 5, 1998)
- ISSN：1520-4995
文摘
Vitronectin is a multifunctional plasma glycoprotein which mayregulate the systems relatedto protease cascades such as the coagulation, fibrinolysis, andcomplement systems as well as cell adhesion.Solid-phase assays and affinity chromatography on immobilizedglycolipids indicated that vitronectinpurified under denaturing conditions bound to sulfatide(Gal(3-SO4)
1-1ceramide), cholesterol3-sulfate,and various phospholipids, but not gangliosides. Only the unfoldedor multimeric form of vitronectinbound to sulfatide, suggesting a conformational dependency of thebinding activity, while vitronectinbound to cholesterol 3-sulfate regardless of its conformational state.The recombinant domains of humanvitronectin and mutants with certain domains deleted were separatelyexpressed in E. coli as fusion proteins.Using the recombinants, sulfatide-, phosphatidylserine-,cholesterol 3-sulfate-, Type I collagen-, heparin-,and -endorphin-binding activities were found to be attributable tohemopexin domain 2 and hemopexindomain 1. The possibility was suggested that the presence of asomatomedin domain and/or connectingregion flanking hemopexin domain 1 inactivated its heparin binding.De-N-glycosylation of plasmavitronectin significantly affected the cholesterol sulfate- andcollagen-binding activities, although its effectswere opposite. These findings suggest that diverse ligand-bindingactivities could be attributed to pexinfamily motifs but that the interdomain interactions and glycosylationsmodulate the ligand binding activitiesof vitronectin.
1-1ceramide), cholesterol3-sulfate,and various phospholipids, but not gangliosides. Only the unfoldedor multimeric form of vitronectinbound to sulfatide, suggesting a conformational dependency of thebinding activity, while vitronectinbound to cholesterol 3-sulfate regardless of its conformational state.The recombinant domains of humanvitronectin and mutants with certain domains deleted were separatelyexpressed in E. coli as fusion proteins.Using the recombinants, sulfatide-, phosphatidylserine-,cholesterol 3-sulfate-, Type I collagen-, heparin-,and -endorphin-binding activities were found to be attributable tohemopexin domain 2 and hemopexindomain 1. The possibility was suggested that the presence of asomatomedin domain and/or connectingregion flanking hemopexin domain 1 inactivated its heparin binding.De-N-glycosylation of plasmavitronectin significantly affected the cholesterol sulfate- andcollagen-binding activities, although its effectswere opposite. These findings suggest that diverse ligand-bindingactivities could be attributed to pexinfamily motifs but that the interdomain interactions and glycosylationsmodulate the ligand binding activitiesof vitronectin.