Title: | NMR characterization of a pH-dependent equilibrium between two folded solution conformations of the pheromone-binding protein from Bombyx mori |
Author(s): | Damberger F; Nikonova L; Horst R; Peng G; Leal WS; Wuthrich K; |
Address: | "Institut fur Molekularbiologie und Biophysik, Eidgenossische Technische Hochschule Honggerberg, Zurich, Switzerland" |
ISSN/ISBN: | 0961-8368 (Print) 1469-896X (Electronic) 0961-8368 (Linking) |
Abstract: | "NMR spectroscopic changes as a function of pH in solutions of the pheromone-binding protein of Bombyx mori (BmPBP) show that BmPBP undergoes a conformational transition between pH 4.9 and 6.0. At pH below 4.9 there is a single 'acid form' (A), and a homogeneous 'basic form' (B) exists at pH above 6.0. Between pH 5 and 6, BmPBP exists as a mixture of A and B in slow exchange on the NMR chemical shift time scale, with the transition midpoint at pH 5.4. The form B has a well-dispersed NMR spectrum, indicating that it represents a more structured, 'closed' conformation than form A, which has a significantly narrower chemical shift dispersion. Conformational transitions of the kind observed here may explain heterogeneity reported for a variety of odorant-binding proteins, and it will be of interest to further investigate possible correlations with pH-dependent regulation of ligand binding and release in the biological function of this class of proteins" |
Keywords: | "Animals Bombyx/*chemistry Carrier Proteins/*chemistry Chromatography, High Pressure Liquid Circular Dichroism Escherichia coli/metabolism Hydrogen-Ion Concentration Insect Proteins/*chemistry Magnetic Resonance Spectroscopy Protein Conformation Protein Is;" |
Notes: | "MedlineDamberger, F Nikonova, L Horst, R Peng, G Leal, W S Wuthrich, K eng Research Support, Non-U.S. Gov't 2000/06/13 Protein Sci. 2000 May; 9(5):1038-41. doi: 10.1110/ps.9.5.1038" |