Uniform TitleProtein free energy landscapes remodeled by ligand binding
NameTalaga, David S. (author), Messina, Troy C. (author), National Institutes of Health, Research Corporation,
SubjectGlucose/galactose binding protein,
Ligand binding (Biochemistry),
DescriptionGlucose/galactose binding protein (GGBP) functions in two different larger systems of proteins used by enteric bacteria for molecular recognition and signaling. Here we report on the thermodynamics of conformational equilibrium distributions of GGBP. Three fluorescence components appear at zero glucose concentration and systematically transition to three components at high glucose concentration. Fluorescence anisotropy correlations, fluorescent lifetimes, thermodynamics, computational structure minimization, and literature work were used to assign the three components as open, closed, and twisted conformations of the protein. The existence of three states at all glucose concentrations indicates that the protein continuously fluctuates about its conformational state space via thermally driven state transitions; glucose biases the populations by reorganizing the free energy profile. These results and their implications are discussed in terms of the two types of specific and nonspecific interactions GGBP has with cytoplasmic membrane proteins.
NoteThis un-edited manuscript has been accepted for publication in Biophysical Journal and is freely available on BioFast at http://www.biophysj.org. The final copyedited version of the paper may be found at http://www.biophysj.org.
NoteNIH F32 GM072328; by Troy C. Messina
NoteNIH R01 GM071684; by David M. Talaga
NoteReseach Corporation No. RI0915
NoteTroy C. Messina was supported by National Institutes of Health, Ruth L. Kirschstein National Research Service Award postdoctoral fellowship F32GM072328. Additional financial support of this work was provided by National Institutes of Health grant R01GM071684, the Research Corporation, No. RI0915, and Rutgers School of Arts and Sciences.
NoteBiophysical Journal 93(2) 579–585
NoteCopyright 2007 by the Biophysical Society
CollectionTalaga, David Collection
Organization NameRutgers, The State University of New Jersey
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