title: Electrophoretic mobility shift in native gels indicates calcium-dependent structural changes of neuronal calcium sensor proteins.
abstract: In proteins of the neuronal calcium sensor (NCS) family, changes in structure as well as function are brought about by the binding of calcium. In this article, we demonstrate that these structural changes, solely due to calcium binding, can be assessed through electrophoresis in native gels. The results demonstrate that the NCS proteins undergo ligand-dependent conformational changes that are detectable in native gels as a gradual decrease in mobility with increasing calcium but not other tested divalent cations such as magnesium, strontium, and barium. Surprisingly, such a gradual change over the entire tested range is exhibited only by the NCS proteins but not by other tested calcium-binding proteins such as calmodulin and S100B, indicating that the change in mobility may be linked to a unique NCS family feature--the calcium-myristoyl switch. Even within the NCS family, the changes in mobility are characteristic of the protein, indicating that the technique is sensitive to the individual features of the protein. Thus, electrophoretic mobility on native gels provides a simple and elegant method to investigate calcium (small ligand)-induced structural changes at least in the superfamily of NCS proteins.
authors.affiliation: Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ 08084, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Viviano
authors.affiliation: Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ 08084, USA.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Krishnan
authors.affiliation: Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ 08084, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.affiliation: Graduate School of Biomedical Sciences, Rowan University, Stratford, NJ 08084, USA; School of Osteopathic Medicine, Rowan University, Stratford, NJ 08084, USA. Electronic address: vvenkat2007@gmail.com.
authors.forename: Venkat
authors.initials: V
authors.lastname: Venkataraman
mesh_terms: D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D063347:Native Polyacrylamide Gel Electrophoresis; D051580:Neuronal Calcium-Sensor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D051580:Neuronal Calcium-Sensor Proteins; D011994:Recombinant Proteins; D002118:Calcium
keywords: Calcium; Electrophoresis; Native gels; Neuronal calcium sensor proteins