[NMR paper] NMR characterization of a pH-dependent equilibrium between two folded solution confor

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NMR characterization of a pH-dependent equilibrium between two folded solution conformations of the pheromone-binding protein from Bombyx mori.

Related Articles NMR characterization of a pH-dependent equilibrium between two folded solution conformations of the pheromone-binding protein from Bombyx mori.

Protein Sci. 2000 May;9(5):1038-41

Authors: Damberger F, Nikonova L, Horst R, Peng G, Leal WS, Wüthrich K

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.

PMID: 10850815 [PubMed - indexed for MEDLINE]



Source: PubMed