[8] Tight binding affinities determined from thermodynamic linkage to protons by titration calorimetry

Doyle, Michael L.; Louie, Godfrey; Monte, Paul R. Dal; Sokoloski, Theodore D.

doi:10.1016/0076-6879(95)59044-7

Cited by 81 publications

(68 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The enthalpy and heat capacity of binding correlate with structural parameters such as hydrogen bond formation and hydrophobic contacts more closely than the Gibbs free energy. Despite structural determination of radicicol binding to Hsc82, the thermodynamic characterization of the linked protonation reactions 35 and comparison with human Hsp90 and isoforms has been insufficiently detailed to understand the binding energetics.…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

Thermodynamics of radicicol binding to human Hsp90 alpha and beta isoforms

Zubrienė¹,

Gutkowska²,

Matulienė³

et al. 2010

Biophysical Chemistry

View full text Add to dashboard Cite

Radicicol is a natural antibiotic that specifically inhibits chaperone Hsp90 activity and binds to its active site with nanomolar affinity. Radicicol has been widely used as a lead compound to generate synthetic analogs with reduced toxicity and increased stability that could be employed clinically. Here we present a detailed thermodynamic description of radicicol binding to human Hsp90 and yeast Hsc82 studied by isothermal titration calorimetry and thermal shift assay.Titrations as a function of pH showed a linked protonation event upon radicicol binding. The intrinsic binding constant and the thermodynamic parameters (including the enthalpy, entropy, and heat capacity) were determined for yeast Hsc82, and human alpha and beta Hsp90. Recent experimental evidence in literature shows that yeast Hsc82 has significant differences from human Hsp90 isozymes. Here we support this by demonstrating differences in radicicol binding thermodynamics to these proteins. The intrinsic enthalpy of radicicol binding to Hsc82 was -46.7 kJ/mol, to Hsp90alpha -70.7 kJ/mol, and to Hsp90beta was -66.8 kJ/mol. The enthalpies of binding were significantly different, while the intrinsic dissociation constants were quite similar,

show abstract

Section: Accepted M Manuscriptmentioning

confidence: 99%

Thermodynamics of radicicol binding to human Hsp90 alpha and beta isoforms

Zubrienė¹,

Gutkowska²,

Matulienė³

et al. 2010

Biophysical Chemistry

View full text Add to dashboard Cite

show abstract

“…In this relationship, ␦ NH 3 ϩ and ␦ NH2 are the 15 holder. The excitation wavelength was set at 310 nm in all the experiments, with the excitation and emission slit widths set at 5 nm.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…15 N NMR spectra were acquired at 30.4 MHz and 25°C on a Varian Unity 300 spectrometer using a recycle delay of 1 second. All 15 15 N resonances were based on those previously reported (9,10). Amine pK a values were determined from plots of the pH dependence of 15 N chemical shifts by nonlinear least-squares analyses using the following relationship:…”

Section: Methodsmentioning

confidence: 99%

“…The number of Neo and CR-Neo amine groups that participate in electrostatic interactions with Ec varies with pH. The Ec binding-linked protonation studies described in the preceding section highlight the importance of electrostatic interactions in driving the formation of the drug-Ec complexes, since such interactions can provide the necessary energy to overcome the energetic cost that is known to be associated with binding-linked ligand protonation reactions (i.e., binding-induced increases in ligand pK a ) (4,13,15,24,27,28,34,35). We quantitatively assessed these electrostatic contributions to the Ec binding of Neo and CR-Neo by monitoring the salt dependence of the drug-RNA binding constants (K a ).…”

Section: Vol 51 2007 Determinants Of Neomycin Antitranslational Actmentioning

confidence: 99%

See 2 more Smart Citations

Defining the Molecular Forces That Determine the Impact of Neomycin on Bacterial Protein Synthesis: Importance of the 2′-Amino Functionality

Barbieri¹,

Kaul²,

Bozza-Hingos³

et al. 2007

Antimicrob Agents Chemother

View full text Add to dashboard Cite

2-Deoxystreptamine (2-DOS) aminoglycosides exert their antibiotic actions by binding to the A site of the 16S rRNA and interfering with bacterial protein synthesis. However, the molecular forces that govern the antitranslational activities of aminoglycosides are poorly understood. Here, we describe studies aimed at elucidating these molecular forces. In this connection, we compare the bactericidal, antitranslational, and rRNA binding properties of the 4,5-disubstituted 2-DOS aminoglycoside neomycin (Neo) and a conformationally restricted analog of Neo (CR-Neo) in which the 2-nitrogen atom is covalently conjugated to the 5؆-carbon atom. The bactericidal potency of Neo exceeds that of CR-Neo, with this enhanced antibacterial activity reflecting a correspondingly enhanced antitranslational potency. Time-resolved fluorescence anisotropy studies suggest that the enhanced antitranslational potency of Neo relative to that of CR-Neo is due to a greater extent of drug-induced reduction in the mobilities of the nucleotides at positions 1492 and 1493 of the rRNA A site. Buffer-and salt-dependent binding studies, coupled with high-resolution structural information, point to electrostatic contacts between the 2-amino functionality of Neo and the host rRNA as being an important modulator of 1492 and 1493 base mobilities and therefore antitranslational activities.The increasing prevalence of multidrug-resistant bacterial infections has made the development of new antibiotics an important focus of current pharmacological research. A thorough understanding of the molecular mechanisms that underlie antibiotic action is an essential component of drug development. The 2-deoxystreptamine (2-DOS) aminoglycosides are potent bactericidal agents that target the 16S rRNA A site in the 30S ribosomal subunit, thereby interfering with bacterial protein synthesis (11,12,14,31,45).Recent structural (11, 16-18, 33, 39, 41-43, 47) and biochemical (23, 46) studies have resulted in the proposal of a model for how aminoglycosides exert their deleterious effects on bacterial translation. This model is based on the premise that two conserved adenine residues at positions 1492 and 1493 of the rRNA A site play critical roles in the translation process. According to the model, A1492 and A1493 are in conformational equilibria between intrahelical and extrahelical states. When in their extrahelical states, A1492 and A1493 interact with the codon-anticodon minihelix. This interaction is favored in the presence of a cognate tRNA anticodon and disfavored in the presence of a noncognate tRNA anticodon. The binding of a 2-DOS aminoglycoside shifts the conformational equilibria of A1492 and A1493 toward the extrahelical state, thereby resulting in an enhanced interaction with the codon-anticodon minihelix, even when the tRNA anticodon is noncognate. The net results of this drug-induced effect are mistranslation, premature termination of translation, and inhibition of translation initiation (12). Consistent with this model for the antitranslational impact of am...

show abstract

Molecular interaction analysis in ligand design using mass transport, kinetic and thermodynamic methods

1996

Self Cite

View full text Add to dashboard Cite

Ligand design in biotechnology is underpinned by the control of molecular affinity. Hence, measuring binding interactions is a key component in designing ligands for such uses as therapeutics, diagnostics, biomaterials and separation science. Mass transport, kinetic and thermodynamic methods have been used for macromolecular interaction analysis but also have potential applicability as direct methods for measuring small molecular interactions. They can enhance the ligand design process by providing the ability to choose ligands based on both their kinetic and thermodynamic binding properties.

show abstract

[8] Tight binding affinities determined from thermodynamic linkage to protons by titration calorimetry

Cited by 81 publications

References 4 publications

Thermodynamics of radicicol binding to human Hsp90 alpha and beta isoforms

Thermodynamics of radicicol binding to human Hsp90 alpha and beta isoforms

Defining the Molecular Forces That Determine the Impact of Neomycin on Bacterial Protein Synthesis: Importance of the 2′-Amino Functionality

Molecular interaction analysis in ligand design using mass transport, kinetic and thermodynamic methods

Contact Info

Product

Resources

About