Interaction of urea with an unfolded protein The DNA‐binding domain of the 434‐repressor

FEBS Letters

Siegal, G.¹  Wüthrich, K.¹  Wider, G.¹  Dötsch, V.¹ 

[1] Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule-Hönggerberg, CH-8093 Zürich, Switzerland

关键词: Protein folding;    Urea denaturation;    Protein solvation;    NMR;    434 repressor(1–63);    N-terminal 63-residue polypeptide fragment from the 434 repressor;    BPTI;    bovine pancreatic trypsin inhibitor;    NMR;    nuclear magnetic resonance;    NOE;    nuclear Overhauser enhancement;    1D;    one-dimensional;    2D;    two-dimensional;    NOESY;    2D NOE spectroscopy in the laboratory frame of reference;    ROESY;    2D NOE spectroscopy in the rotating frame;    COSY;    2D correlation spectroscopy;    INEPT;    Insensitive Nuclei Enhanced by Polarization Transfer;    σ NOE;    cross relaxation rate in the laboratory frame;    σ ROE;    cross relaxation rate in the rotating frame;   

DOI  :  10.1016/0014-5793(95)00459-M

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown