title: Advantages of synchrotron radiation circular dichroism spectroscopy to study intrinsically disordered proteins.
abstract: The unordered secondary structural content of an intrinsically disordered protein (IDP) is susceptible to conformational changes induced by many different external factors, such as the presence of organic solvents, removal of water, changes in temperature, binding to partner molecules, and interaction with lipids and/or other ligands. In order to characterize the high-flexibility nature of an IDP, circular dichroism (CD) spectroscopy is a particularly useful method due to its capability of monitoring both subtle and remarkable changes in different environments, relative ease in obtaining measurements, the small amount of sample required, and the capability for sample recovery (sample not damaged) and others. Using synchrotron radiation as the light source for CD spectroscopy represents the state-of-the-art version of this technique with feasibility of accessing the lower wavelength UV region, and therefore presenting a series of advantages over conventional circular dichroism (cCD) to monitor a protein conformational behavior, check protein stability, detect ligand binding, and many others. In this paper, we have performed a comparative study using cCD and SRCD methods for investigating the secondary structure and the conformational behavior of natively unfolded proteins: MEG-14 and soybean trypsin inhibitor. We show that the SRCD technique greatly improves the analysis and accuracy of the studies on the conformations of IDPs.
authors.affiliation: Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, Brazil.
authors.forename: Patricia S
authors.initials: PS
authors.lastname: Kumagai
authors.affiliation: Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: DeMarco
authors.affiliation: Depto. Física Aplicada, Grupo de Cristalografia, Instituto de Física, Universidade de São Paulo, Rua do Matão 1371, São Paulo, SP, 05508-090, Brazil. zeluiz@if.usp.br.
authors.forename: Jose L S
authors.initials: JLS
authors.lastname: Lopes
mesh_terms: D000818:Animals; D002942:Circular Dichroism / Q000295:instrumentation*; D015801:Helminth Proteins / Q000737:chemistry; D064267:Intrinsically Disordered Proteins / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry; D000072417:Protein Domains; D012550:Schistosoma mansoni; D012995:Solubility; D017356:Synchrotrons; D014867:Water / Q000737:chemistry
chemical_list: D015801:Helminth Proteins; D064267:Intrinsically Disordered Proteins; D010940:Plant Proteins; D014867:Water
keywords: Intrinsically disordered protein; Protein conformation; Secondary structure; Synchrotron radiation circular dichroism spectroscopy