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Mehta AY, Heimburg-Molinaro J, Cummings RD, Goth CK. Emerging patterns of tyrosine sulfation and O-glycosylation cross-talk and co-localization. Curr Opin Struct Biol 2020; 62:102-111. [PMID: 31927217 DOI: 10.1016/j.sbi.2019.12.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/26/2019] [Accepted: 12/02/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Akul Y Mehta
- Department of Surgery, Beth Israel Deaconess Medical Center, National Center for Functional Glycomics, Harvard Medical School, Boston, MA, 02215, USA
| | - Jamie Heimburg-Molinaro
- Department of Surgery, Beth Israel Deaconess Medical Center, National Center for Functional Glycomics, Harvard Medical School, Boston, MA, 02215, USA
| | - Richard D Cummings
- Department of Surgery, Beth Israel Deaconess Medical Center, National Center for Functional Glycomics, Harvard Medical School, Boston, MA, 02215, USA
| | - Christoffer K Goth
- Department of Surgery, Beth Israel Deaconess Medical Center, National Center for Functional Glycomics, Harvard Medical School, Boston, MA, 02215, USA
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Toomey CG, Weiss D, Chant A, Ackerman M, Ahlers BA, Lam YW, Ricciardi C, Bourne D, Kraemer-Chant CM. Development and Applications of a Calmodulin-Based Fusion Protein System for the Expression and Purification of WW and Zinc Finger Modules. ADVANCES IN BIOLOGICAL CHEMISTRY 2017; 7:89-106. [PMID: 31482041 PMCID: PMC6719719 DOI: 10.4236/abc.2017.72006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Calmodulin from Homo sapiens is an α-helical calcium-binding protein that expresses to high levels in E. coli. When the N-terminus of a calmodulin variant is bound to Ca2+, it undergoes a conformational change, exposing hydrophobic pockets. This property can be utilized for purification purposes, as these pockets bind to phenyl sepharose resin with high affinity. Washing with EDTA chelates the Ca2+ ions from the protein, inducing a conformational change back to the more folded state and eluting the protein from the column. We describe herein the use of a protein expression and purification technique using the calmodulin variant and a short linker for proteolytic cleavage by the mutant NIa-Pro tobacco etch virus protease. We have shown this approach to be useful in obtaining purified quantities of various small proteins that could not be expressed using other methods, including high enough concentrations of a designed WW domain protein for NMR structural analysis. We have also obtained promising results on the usefulness of this procedure to express and purify zinc finger proteins without the addition of zinc ions or other cofactors.
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Affiliation(s)
| | - David Weiss
- Department of Chemistry, Saint Michael’s College, Colchester, Vermont, USA
| | - Alan Chant
- Department of Chemistry, University of Vermont, Burlington, Vermont, USA
| | - Megan Ackerman
- Department of Chemistry, Saint Michael’s College, Colchester, Vermont, USA
| | - Bethany A. Ahlers
- Department of Biology, University of Vermont, Burlington, Vermont, USA
- Vermont Genetics Network Proteomics Facility, University of Vermont, Burlington, Vermont, USA
| | - Ying-Wai Lam
- Department of Biology, University of Vermont, Burlington, Vermont, USA
- Vermont Genetics Network Proteomics Facility, University of Vermont, Burlington, Vermont, USA
| | | | - Dana Bourne
- Department of Biochemistry, University of Vermont, Burlington, Vermont, USA
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3
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Lechtenberg BC, Freund SMV, Huntington JA. GpIbα interacts exclusively with exosite II of thrombin. J Mol Biol 2013; 426:881-93. [PMID: 24316004 PMCID: PMC3919161 DOI: 10.1016/j.jmb.2013.11.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/21/2013] [Accepted: 11/23/2013] [Indexed: 11/09/2022]
Abstract
Activation of platelets by the serine protease thrombin is a critical event in haemostasis. This process involves the binding of thrombin to glycoprotein Ibα (GpIbα) and cleavage of protease-activated receptors (PARs). The N-terminal extracellular domain of GpIbα contains an acidic peptide stretch that has been identified as the main thrombin binding site, and both anion binding exosites of thrombin have been implicated in GpIbα binding, but it remains unclear how they are involved. This issue is of critical importance for the mechanism of platelet activation by thrombin. If both exosites bind to GpIbα, thrombin could potentially act as a platelet adhesion molecule or receptor dimerisation trigger. Alternatively, if only a single site is involved, GpIbα may serve as a cofactor for PAR-1 activation by thrombin. To determine the involvement of thrombin's two exosites in GpIbα binding, we employed the complementary methods of mutational analysis, binding studies, X-ray crystallography and NMR spectroscopy. Our results indicate that the peptide corresponding to the C-terminal portion of GpIbα and the entire extracellular domain bind exclusively to thrombin's exosite II. The interaction of thrombin with GpIbα thus serves to recruit thrombin activity to the platelet surface while leaving exosite I free for PAR-1 recognition. We analysed interactions of the platelet receptor GpIbα with thrombin using three complementary methods. GpIbα exclusively binds to exosite II of thrombin. Exosite I remains available for binding to other ligands. GpIbα recruits thrombin to the platelet membrane as a cofactor for PAR-1 cleavage.
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Affiliation(s)
- Bernhard C Lechtenberg
- Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - Stefan M V Freund
- MRC Laboratory for Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - James A Huntington
- Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, United Kingdom.
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Jennings NS, Smethurst PA, Knight CG, O'Connor MN, Joutsi-Korhonen L, Stafford P, Stephens J, Garner SF, Harmer IJ, Farndale RW, Watkins NA, Ouwehand WH. Production of calmodulin-tagged proteins in Drosophila Schneider S2 cells: A novel system for antigen production and phage antibody isolation. J Immunol Methods 2006; 316:75-83. [PMID: 17027020 DOI: 10.1016/j.jim.2006.08.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Revised: 08/14/2006] [Accepted: 08/16/2006] [Indexed: 11/28/2022]
Abstract
We report the development of an expression system for the production of soluble, calmodulin (CaM)-tagged proteins in Drosophila Schneider S2 cells and the subsequent use of these proteins for the selection of phage displayed antibodies. The CaM-tag permitted the purification of recombinant protein to >90% purity in a single step at yields of >20 mg/l. Using platelet glycoprotein VI (GP6) as a model, we demonstrated that the recombinant CaM-tagged protein was post-translationally N-glycosylated and had identical ligand specificity to native protein. A novel selection strategy, exploiting the CaM tag, was then used to isolate four single chain Fv fragments (scFvs) specific for GP6 from a non-immune phage display library. In contrast to other selection methods, which can result in antibodies that do not recognise native protein, all of the scFvs we selected bound cell surface expressed GP6. In conclusion, the production of CaM-tagged proteins in Drosophila Schneider S2 cells and the selection strategy reported here offer advantages over previously published methods, including simple culture conditions, rapid protein purification, specific elution of phage antibodies and preferential selection of phage antibodies that recognise native, cell surface expressed protein.
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Affiliation(s)
- Nicola S Jennings
- Department of Haematology, University of Cambridge and the National Blood Service Cambridge, Cambridge, UK
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Ulrichts H, Vanhoorelbeke K, Girma JP, Lenting PJ, Vauterin S, Deckmyn H. The von Willebrand factor self-association is modulated by a multiple domain interaction. J Thromb Haemost 2005; 3:552-61. [PMID: 15748246 DOI: 10.1111/j.1538-7836.2005.01209.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Platelet adhesion and aggregation at sites of vascular injury exposed to rapid blood flow require von Willebrand factor (VWF). VWF becomes immobilized by binding to subendothelial components or by a self-association at the interface of soluble and surface-bound VWF. OBJECTIVES As this self-association has been demonstrated only under shear conditions, our first goal was to determine whether the same interaction could be observed under static conditions. Furthermore, we wanted to identify VWF domain(s) important for this self-association. RESULTS Biotinylated VWF (b-VWF) interacted dose-dependently and specifically with immobilized VWF in an enzyme-linked immunosorbent assay (ELISA) assay, showing that shear is not necessary to induce the VWF self-association. Whereas anti-VWF monoclonal antibodies (mAbs) had no effect on the self-association, the proteolytic VWF-fragments SpII(1366-2050) and SpIII(1-1365) inhibited the b-VWF-VWF interaction by 70 and 80%, respectively. Moreover, a specific binding of b-VWF to immobilized Sp-fragments was demonstrated. Finally, both biotinylated SpII and SpIII were able to bind specifically to both immobilized SpII and SpIII. Similar results were observed under flow conditions, which confirmed the functional relevance of our ELISA system. CONCLUSION We have developed an ELISA binding assay in which a specific VWF self-association under static conditions can be demonstrated. Our results suggest a multiple domain interaction between immobilized and soluble VWF.
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Affiliation(s)
- H Ulrichts
- KU Leuven Campus Kortrijk, Kortrijk, Belgium
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Shimizu A, Matsushita T, Kondo T, Inden Y, Kojima T, Saito H, Hirai M. Identification of the Amino Acid Residues of the Platelet Glycoprotein Ib (GPIb) Essential for the von Willebrand Factor Binding by Clustered Charged-to-Alanine Scanning Mutagenesis. J Biol Chem 2004; 279:16285-94. [PMID: 14757772 DOI: 10.1074/jbc.m307230200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
At the site of vascular injury, von Willebrand factor (VWF) mediates platelet adhesion to subendothelial connective tissue through binding to the N-terminal domain of the alpha chain of platelet glycoprotein Ib (GPIbalpha). To elucidate the molecular mechanisms of the binding, we have employed charged-to-alanine scanning mutagenesis of the soluble fragment containing the N-terminal 287 amino acids of GPIbalpha. Sixty-two charged amino acids were changed singly or in small clusters, and 38 mutant constructs were expressed in the supernatant of 293T cells. Each mutant was assayed for binding to several monoclonal antibodies for human GPIbalpha and for ristocetin-induced and botrocetin-induced binding of 125I-labeled human VWF. Mutations at Glu128, Glu172, and Asp175 specifically decreased both ristocetin- and botrocetin-induced VWF binding, suggesting that these sites are important for VWF binding of platelet GPIb. Monoclonal antibody 6D1 inhibited ristocetin- and botrocetin-induced VWF binding, and a mutation at Glu125 specifically reduced the binding to 6D1. In contrast, antibody HPL7 had no effect for VWF binding, and mutant E121A reduced the HPL7 binding. Mutations at His12 and Glu14 decreased the ristocetin-induced VWF binding with normal botrocetin-induced binding. Crystallographic modeling of the VWF-GPIbalpha complex indicated that Glu128 and Asp175 form VWF binding sites; the binding of 6D1 to Glu125 interrupts the VWF binding of Glu128, but HPL7 binding to Glu121 has no effect on VWF binding. Moreover, His12 and Glu14 contact with Glu613 and Arg571 of VWF A1 domain, whose mutations had shown similar phenotype. These findings indicated the novel binding sites required for VWF binding of human GPIbalpha.
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Affiliation(s)
- Atsuya Shimizu
- First Department of Internal Medicine, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
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Ulrichts H, Vanhoorelbeke K, Cauwenberghs S, Vauterin S, Kroll H, Santoso S, Deckmyn H. von Willebrand factor but not alpha-thrombin binding to platelet glycoprotein Ibalpha is influenced by the HPA-2 polymorphism. Arterioscler Thromb Vasc Biol 2003; 23:1302-7. [PMID: 12775575 DOI: 10.1161/01.atv.0000079510.23517.43] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Glycoprotein (GP) Ibalpha is the functionally dominant subunit of the platelet GPIb-IX-V receptor complex. The N-terminal domain of the GPIbalpha chain contains binding sites for alpha-thrombin and von Willebrand factor (VWF). The human platelet alloantigen (HPA)-2 polymorphism of the GPIbalpha gene is associated with a C/T transition at nucleotide 1018, resulting in a Thr/Met dimorphism at residue 145 of GPIbalpha. To study the structural and functional effects of this dimorphism, N-terminal fragments (AA1-289) of the HPA-2a and HPA-2b alloform of GPIbalpha expressed in CHO cells were used. METHODS AND RESULTS Of 74 moAbs directed against human GPIbalpha, 2 antibodies with epitope between AA1-59 could differentiate between both alloforms. In addition, VWF bound with a higher affinity to the recombinant HPA-2a fragment or to homozygous HPA-2a platelets. In contrast, no difference was found in the binding of alpha-thrombin to the recombinant alloform fragments or of antibodies directed against the alpha-thrombin binding anionic sulfated tyrosine sequence (AA269-282). CONCLUSIONS Whereas the Thr145Met dimorphism does not affect alpha-thrombin binding, it does influence the conformation of the N-terminal flanking region and first leucine-rich repeat of GPIbalpha and by this has an effect on VWF binding.
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Affiliation(s)
- Hans Ulrichts
- Laboratory for Thrombosis Research, IRC, KULeuven Campus Kortrijk, E. Sabbelaan 53, 8500 Kortrijk, Belgium
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