Title: | Effects of protein-pheromone complexation on correlated chemical shift modulations |
Author(s): | Perazzolo C; Wist J; Loth K; Poggi L; Homans S; Bodenhausen G; |
Address: | "Institut des Sciences et Ingenierie Chimiques, Ecole Polytechnique Federale de Lausanne, BCH, 1015, Lausanne, Switzerland" |
DOI: | 10.1007/s10858-005-3355-y |
ISSN/ISBN: | 0925-2738 (Print) 0925-2738 (Linking) |
Abstract: | "Major urinary protein (MUP) is a pheromone-carrying protein of the lipocalin family. Previous studies by isothermal titration calorimetry (ITC) show that the affinity of MUP for the pheromone 2-methoxy-3-isobutylpyrazine (IBMP) is mainly driven by enthalpy, with a small unfavourable entropic contribution. Entropic terms can be attributed in part to changes in internal motions of the protein upon binding. Slow internal motions can lead to correlated or anti-correlated modulations of the isotropic chemical shifts of carbonyl C' and amide N nuclei. Correlated chemical shift modulations (CSM/CSM) in MUP have been determined by measuring differences of the transverse relaxation rates of zero- and double-quantum coherences ZQCC'N and DQCC'N, and by accounting for the effects of correlated fluctuations of dipole-dipole couplings (DD/DD) and chemical shift anisotropies (CSA/CSA). The latter can be predicted from tensor parameters of C' and N nuclei that have been determined in earlier work. The effects of complexation on slow time-scale protein dynamics can be determined by comparing the temperature dependence of the relaxation rates of APO-MUP (i.e., without ligand) and HOLO-MUP (i.e., with IBMP as a ligand)" |
Keywords: | "Amino Acids Crystallography, X-Ray Ligands Magnetic Resonance Spectroscopy Models, Molecular Pheromones/*chemistry Protein Binding Protein Conformation Proteins/*chemistry Temperature;" |
Notes: | "MedlinePerazzolo, Chiara Wist, Julien Loth, Karine Poggi, Luisa Homans, Steve Bodenhausen, Geoffrey eng Research Support, Non-U.S. Gov't Netherlands 2005/12/13 J Biomol NMR. 2005 Dec; 33(4):233-42. doi: 10.1007/s10858-005-3355-y" |