title: Self-Assembly of Human Profilin-1 Detected by Carr-Purcell-Meiboom-Gill Nuclear Magnetic Resonance (CPMG NMR) Spectroscopy.
abstract: Protein oligomerization in the cell has important implications for both health and disease, and an understanding of the mechanisms by which proteins can self-associate is, therefore, of critical interest. Initial stages of the oligomerization process can be hard to detect, as they often involve the formation of sparsely populated and transient states that are difficult to characterize by standard biophysical approaches. Using relaxation dispersion nuclear magnetic resonance spectroscopy, we study the oligomerization of human profilin-1, a protein that regulates the polymerization of actin. We show that in solution and at millimolar concentrations profilin-1 is predominantly monomeric. However, fits of concentration-dependent relaxation data are consistent with the formation of a higher-order oligomer that is generated via a multistep process. Together with crystallographic data for profilin-2, a homologue of the protein studied here, our results suggest that profilin-1 forms a sparsely populated tetrameric conformer in solution.
authors.affiliation: Departments of Molecular Genetics, Biochemistry and Chemistry, The University of Toronto , Toronto, Ontario M5S 1A8, Canada.
authors.forename: Enrico
authors.identifier: 0000-0002-2941-7155
authors.initials: E
authors.lastname: Rennella
authors.affiliation: Departments of Molecular Genetics, Biochemistry and Chemistry, The University of Toronto , Toronto, Ontario M5S 1A8, Canada.
authors.forename: Ashok
authors.initials: A
authors.lastname: Sekhar
authors.affiliation: Departments of Molecular Genetics, Biochemistry and Chemistry, The University of Toronto , Toronto, Ontario M5S 1A8, Canada.|Program in Molecular Structure and Function, Hospital for Sick Children , 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
authors.forename: Lewis E
authors.initials: LE
authors.lastname: Kay
mesh_terms: D000199:Actins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D051304:Profilins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000072417:Protein Domains; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D000199:Actins; C495738:PFN1 protein, human; C495741:PFN2 protein, human; D051304:Profilins; D011994:Recombinant Proteins