Protein free energy landscapes remodeled by ligand binding

Troy C. Messina, David S. Talaga

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Glucose/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.

Original languageEnglish
Pages (from-to)579-585
Number of pages7
JournalBiophysical Journal
Volume93
Issue number2
DOIs
StatePublished - Jul 2007

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Ligands
Glucose
Proteins
Thermodynamics
Protein Conformation
Fluorescence Polarization
Enterobacteriaceae
Membrane Proteins
Fluorescence
Cell Membrane
Population
galactose-binding protein

Cite this

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Protein free energy landscapes remodeled by ligand binding. / Messina, Troy C.; Talaga, David S.

In: Biophysical Journal, Vol. 93, No. 2, 07.2007, p. 579-585.

Research output: Contribution to journalArticle

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