title: Interaction of urea with an unfolded protein. The DNA-binding domain of the 434-repressor.
abstract: Experimental techniques are presented for the observation of the solvation of the unfolded form of a globular protein, the N-terminal 63-residue polypeptide from the 434 repressor, in 7 M aqueous urea solution by both water and urea. With the use of 15N-labelled urea it is demonstrated that the cross sections through two-dimensional nuclear Overhauser enhancement (NOE) spectra at the chemical shifts of H2O and urea both contain direct NOEs with the protein, under conditions where exchange peaks are observed only in the water cross section. A preliminary analysis of the data showed that the residence times of urea molecules in solvation sites near the methyl groups of Val, Leu and Ile are significantly longer than those of water molecules in the same sites.
authors.affiliation: Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule-Hönggerberg, Zürich, Switzerland.
authors.forename: V
authors.initials: V
authors.lastname: Dötsch
authors.forename: G
authors.initials: G
authors.lastname: Wider
authors.forename: G
authors.initials: G
authors.lastname: Siegal
authors.forename: K
authors.initials: K
authors.lastname: Wüthrich
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D017123:Bacteriophage T7 / Q000737:chemistry / Q000235:genetics; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011485:Protein Binding; D017510:Protein Folding; D011522:Protons; D012097:Repressor Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012996:Solutions; D014508:Urea / Q000737:chemistry / Q000378:metabolism*; D014764:Viral Proteins; D014867:Water / Q000737:chemistry
chemical_list: C063367:434-repressor protein, Bacteriophage 434; D000596:Amino Acids; D004268:DNA-Binding Proteins; D011522:Protons; D012097:Repressor Proteins; D012996:Solutions; D014764:Viral Proteins; D014867:Water; D014508:Urea