title: T-shaped arrangement of the recombinant agrin G3-IgG Fc protein.
abstract: Agrin is a large heparin sulphate proteoglycan with multiple domains, which is located in the extracellular matrix. The C-terminal G3 domain of agrin is functionally one of the most important domains. It harbors an α-dystroglycan binding site and carries out acetylcholine receptor clustering activities. In the present study, we have fused the G3 domain of agrin to an IgG Fc domain to produce a G3-Fc fusion protein that we intend to use as a tool to investigate new binding partners of agrin. As a first step of the study, we have characterized the recombinant fusion protein using a multidisciplinary approach using dynamic light scattering, analytical ultracentrifugation and small angle X-ray scattering (SAXS). Interestingly, our SAXS analysis using the high-resolution structures of G3 and Fc domain as models indicates that the G3-Fc protein forms a T-shaped molecule with the G3 domains extruding perpendicularly from the Fc scaffold. To validate our models, we have used the program HYDROPRO to calculate the hydrodynamic properties of the solution models. The calculated values are in excellent agreement with those determined experimentally.
authors: Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T2N2, Canada.
authors: Trushar R
authors: TR
authors: Patel
authors: Markus
authors: M
authors: Meier
authors: Jianhua
authors: J
authors: Li
authors: Gordon
authors: G
authors: Morris
authors: Arthur J
authors: AJ
authors: Rowe
authors: Jörg
authors: J
authors: Stetefeld
mesh_terms: D018171:Agrin / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002645:Chickens; D015870:Gene Expression; D006801:Humans; D057446:Hydrodynamics; D007141:Immunoglobulin Fc Fragments / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D007074:Immunoglobulin G / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D053838:Scattering, Small Angle; D014461:Ultracentrifugation; D014961:X-Ray Diffraction
chemical_list: D018171:Agrin; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D011993:Recombinant Fusion Proteins