Disease relevance of glnH

• The crystal structure of the glutamine-binding protein (GlnBP) from Escherichia coli in a ligand-free "open" conformational state has been determined by isomorphous replacement methods and refined to an R-value of 21.4% at 2.3 A resolution [1].

High impact information on glnH

• A model of the "closed form" GlnBP-Gln complex has been proposed based on the crystal structures of the histidine-binding protein-His complex and "open form" GlnBP [1].
• The aim of this work was to study the conformational changes of the Escherichia coli glutamine-binding protein (GlnBP) induced by GdnHCl and the effect of the binding of glutamine (Gln) on these processes [2].
• These results have unambiguously determined the ligand orientation with respect to the imidazole ring of His156, which is an important first step in refining the ligand-binding-site model of GlnBP in general [3].
• Time correlated single photon counting measurements of tryptophan (Trp) fluorescence intensity decay and other spectroscopic studies were performed on glutamine-binding protein (GlnBP) from Escherichia coli [4].
• Significantly, the influence of the ligand on GlnBP dynamics is similar to that previously observed in simulations of rat glutamate receptor (GluR2) ligand-binding domain [5].

Chemical compound and disease context of glnH

• Glutamine-binding protein (GlnBP) is an essential component of the glutamine transport system in Escherichia coli [3].

Biological context of glnH

• We have developed a reagentless optical biosensor for glutamine based on the Escherichia coli glutamine binding protein (GlnBP) [6].
• Mass spectrometry experiments demonstrated that GlnBP binds the following amino acid sequence: XXQPQPQQQQQQQQQQQQL, present only into the toxic prolamines [7].

Associations of glnH with chemical compounds

• Rotational-echo double-resonance (REDOR) solid-state nuclear magnetic resonance (NMR) has been used to determine internuclear distances in the complex of GlnBP and its ligand, L-glutamine [3].
• The S179C variant of GlnBP was labeled at the -SH and N-terminal positions with acrylodan and ruthenium bis-(2,2'-bipyridyl)-1,10-phenanthroline-9-isothiocyanate, respectively [8].

Analytical, diagnostic and therapeutic context of glnH

• To this end, GdnHCl-induced unfolding of GlnBP alone and its GlnBP-Gln complex was studied by protein intrinsic fluorescence, ANS emission fluorescence, and far- and near-UV circular dichroism spectroscopy [2].
• The engineered GlnBP is a first step toward the development of a nonenzymatic biosensor capable of determining glutamine concentrations in cell cultures [6].
• The fluorescence emission of acrylodan and 2-(4'-(iodoacetamido)anilino)naphthalene-6-sulfonic acid (IAANS) attached to GlnBP mutant S179C was shown to decrease 65 and 35%, respectively, upon titration with increasing amounts of glutamine (0 to 6.4 microM; K(Dapp) 160 nM) [6].
• Affinity chromatography experiments together with mass spectrometry experiments demonstrated that GlnBP can bind the following amino acid sequence XXQPQPQQQQQQQQQQQQL [9].

References