title: DSC studies of a family of natively disordered fragments from Escherichia coli thioredoxin: surface burial in intrinsic coils.
abstract: The accumulating data from proteome analysis indicates that numerous proteins have segments and/or domains, involved in regulatory functions of the eukaryotic cell, which are entirely unstructured under physiological conditions, challenging the structure-function paradigm. Although many such natively unfolded proteins have been structurally analyzed by NMR spectroscopy, little is known about solvent inaccessible surfaces in premolten globules and intrinsic coils. Recent DSC studies of two protein fragments have shown a promising way to estimate the predominantly hydrophobic buried surfaces [Georgescu, R. E., García-Mira, M. M., Tasayco, M. L., and Sánchez-Ruiz, J. M. (2001) Eur. J. Biochem. 268, 1-10]. Here we report a systematic heat capacity analysis of a family of natively disordered complementary fragments of oxidized Escherichia coli thioredoxin (1-31/32-108, 1-37/38-108, 1-50/51-108, and 38-73) which provides insights into the local and nonlocal interactions contributing to the burial of predominantly hydrophobic surface in intrinsic coils.
authors.affiliation: Biochemistry Division, Department of Chemistry, City College of New York, 138(th) Street and Convent Avenue, New York, New York 10031, USA.
authors.forename: Carla
authors.initials: C
authors.lastname: Mendoza
authors.forename: Francisco
authors.initials: F
authors.lastname: Figueirido
authors.forename: María Luisa
authors.initials: ML
authors.lastname: Tasayco
mesh_terms: D002152:Calorimetry, Differential Scanning; D002850:Chromatography, Gel; D004926:Escherichia coli / Q000737:chemistry*; D006358:Hot Temperature; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000737:chemistry; D013879:Thioredoxins / Q000737:chemistry*
chemical_list: D010446:Peptide Fragments; D013879:Thioredoxins