The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Michael D. Fayer - One of the best experts on this subject based on the ideXlab platform.
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Viscosity-Dependent Protein Dynamics
Biophysical Journal, 2007Co-Authors: Ilya J Finkelstein, Aaron M. Massari, Michael D. FayerAbstract:Spectrally resolved stimulated vibrational echo spectroscopy is used to investigate the dependence of fast Protein Dynamics on bulk solution viscosity at room temperature in four heme Proteins: hemoglobin, myoglobin, a myoglobin mutant with the distal histidine replaced by a valine (H64V), and a cytochrome c552 mutant with the distal methionine replaced by an alanine (M61A). Fructose is added to increase the viscosity of the aqueous Protein solutions over many orders of magnitude. The fast Dynamics of the four globular Proteins were found to be sensitive to solution viscosity and asymptotically approached the dynamical behavior that was previously observed in room temperature sugar glasses. The viscosity-dependent Protein Dynamics are analyzed in the context of a viscoelastic relaxation model that treats the Protein as a deformable breathing sphere. The viscoelastic model is in qualitative agreement with the experimental data but does not capture sufficient system detail to offer a quantitative description of the underlying fluctuation amplitudes and relaxation rates. A calibration method based on the near-infrared spectrum of water overtones was constructed to accurately determine the viscosity of small volumes of Protein solutions.
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Viscosity-dependent Protein Dynamics
Biophysical Journal, 2007Co-Authors: Ilya J Finkelstein, Aaron M. Massari, Michael D. FayerAbstract:Spectrally resolved stimulated vibrational echo spectroscopy is used to investigate the dependence of fast Protein Dynamics on bulk solution viscosity at room temperature in four heme Proteins: hemoglobin, myoglobin, a myoglobin mutant with the distal histidine replaced by a valine (H64V), and a cytochrome c552 mutant with the distal methionine replaced by an alanine (M61A). Fructose is added to increase the viscosity of the aqueous Protein solutions over many orders of magnitude. The fast Dynamics of the four globular Proteins were found to be sensitive to solution viscosity and asymptotically approached the dynamical behavior that was previously observed in room temperature sugar glasses. The viscosity-dependent Protein Dynamics are analyzed in the context of a viscoelastic relaxation model that treats the Protein as a deformable breathing sphere. The viscoelastic model is in qualitative agreement with the experimental data but does not capture sufficient system detail to offer a quantitative description of the underlying fluctuation amplitudes and relaxation rates. A calibration method based on the near-infrared spectrum of water overtones was constructed to accurately determine the viscosity of small volumes of Protein solutions. © 2007 by the Biophysical Society.
Ilya J Finkelstein - One of the best experts on this subject based on the ideXlab platform.
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Viscosity-Dependent Protein Dynamics
Biophysical Journal, 2007Co-Authors: Ilya J Finkelstein, Aaron M. Massari, Michael D. FayerAbstract:Spectrally resolved stimulated vibrational echo spectroscopy is used to investigate the dependence of fast Protein Dynamics on bulk solution viscosity at room temperature in four heme Proteins: hemoglobin, myoglobin, a myoglobin mutant with the distal histidine replaced by a valine (H64V), and a cytochrome c552 mutant with the distal methionine replaced by an alanine (M61A). Fructose is added to increase the viscosity of the aqueous Protein solutions over many orders of magnitude. The fast Dynamics of the four globular Proteins were found to be sensitive to solution viscosity and asymptotically approached the dynamical behavior that was previously observed in room temperature sugar glasses. The viscosity-dependent Protein Dynamics are analyzed in the context of a viscoelastic relaxation model that treats the Protein as a deformable breathing sphere. The viscoelastic model is in qualitative agreement with the experimental data but does not capture sufficient system detail to offer a quantitative description of the underlying fluctuation amplitudes and relaxation rates. A calibration method based on the near-infrared spectrum of water overtones was constructed to accurately determine the viscosity of small volumes of Protein solutions.
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Viscosity-dependent Protein Dynamics
Biophysical Journal, 2007Co-Authors: Ilya J Finkelstein, Aaron M. Massari, Michael D. FayerAbstract:Spectrally resolved stimulated vibrational echo spectroscopy is used to investigate the dependence of fast Protein Dynamics on bulk solution viscosity at room temperature in four heme Proteins: hemoglobin, myoglobin, a myoglobin mutant with the distal histidine replaced by a valine (H64V), and a cytochrome c552 mutant with the distal methionine replaced by an alanine (M61A). Fructose is added to increase the viscosity of the aqueous Protein solutions over many orders of magnitude. The fast Dynamics of the four globular Proteins were found to be sensitive to solution viscosity and asymptotically approached the dynamical behavior that was previously observed in room temperature sugar glasses. The viscosity-dependent Protein Dynamics are analyzed in the context of a viscoelastic relaxation model that treats the Protein as a deformable breathing sphere. The viscoelastic model is in qualitative agreement with the experimental data but does not capture sufficient system detail to offer a quantitative description of the underlying fluctuation amplitudes and relaxation rates. A calibration method based on the near-infrared spectrum of water overtones was constructed to accurately determine the viscosity of small volumes of Protein solutions. © 2007 by the Biophysical Society.
Balázs Szalontai - One of the best experts on this subject based on the ideXlab platform.
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Membrane Protein Dynamics: limited lipid control
PMC Biophysics, 2009Co-Authors: Balázs SzalontaiAbstract:Correlation of lipid disorder with membrane Protein Dynamics has been studied with infrared spectroscopy, by combining data characterizing lipid phase, Protein structure and, via hydrogen-deuterium (H/D) exchange, Protein Dynamics. The key element was a new measuring scheme, by which the combined effects of time and temperature on the H/D exchange could be separated. Cyanobacterial and plant thylakoid membranes, mammalian mitochondria membranes, and for comparison, lysozyme were investigated. In dissolved lysozyme, as a function of temperature, H/D exchange involved only reversible movements (the secondary structure did not change considerably); heat-denaturing was a separate event at much higher temperature. Around the low-temperature functioning limit of the biomembranes, lipids affected Protein Dynamics since changes in fatty acyl chain disorders and H/D exchange exhibited certain correlation. H/D exchange remained low in all membranes over physiological temperatures. Around the high-temperature functioning limit of the membranes, the exchange rates became higher. When temperature was further increased, H/D exchange rates went over a maximum and afterwards decreased (due to full H/D exchange and/or Protein denaturing). Maximal H/D exchange rate temperatures correlated neither with the disorder nor with the unsaturation of lipids. In membrane Proteins, in contrast to lysozyme, the onsets of sizable H/D exchange rates were the onsets of irreversible denaturing as well. Seemingly, at temperatures where Protein self-Dynamics allows large-scale H/D exchange, lipid-Protein coupling is so weak that Proteins prefer aggregating to limit the exposure of their hydrophobic surface regions to water. In all membranes studied, Dynamics seemed to be governed by lipids around the low-temperature limit, and by Proteins around the high-temperature limit of membrane functionality. PACS codes : 87.14.ep, 87.14.cc, 87.16.D
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Membrane Protein Dynamics: limited lipid control.
Pmc Biophysics, 2009Co-Authors: Balázs SzalontaiAbstract:Correlation of lipid disorder with membrane Protein Dynamics has been studied with infrared spectroscopy, by combining data characterizing lipid phase, Protein structure and, via hydrogen-deuterium (H/D) exchange, Protein Dynamics. The key element was a new measuring scheme, by which the combined effects of time and temperature on the H/D exchange could be separated. Cyanobacterial and plant thylakoid membranes, mammalian mitochondria membranes, and for comparison, lysozyme were investigated. In dissolved lysozyme, as a function of temperature, H/D exchange involved only reversible movements (the secondary structure did not change considerably); heat-denaturing was a separate event at much higher temperature. Around the low-temperature functioning limit of the biomembranes, lipids affected Protein Dynamics since changes in fatty acyl chain disorders and H/D exchange exhibited certain correlation. H/D exchange remained low in all membranes over physiological temperatures. Around the high-temperature functioning limit of the membranes, the exchange rates became higher. When temperature was further increased, H/D exchange rates went over a maximum and afterwards decreased (due to full H/D exchange and/or Protein denaturing). Maximal H/D exchange rate temperatures correlated neither with the disorder nor with the unsaturation of lipids. In membrane Proteins, in contrast to lysozyme, the onsets of sizable H/D exchange rates were the onsets of irreversible denaturing as well. Seemingly, at temperatures where Protein self-Dynamics allows large-scale H/D exchange, lipid-Protein coupling is so weak that Proteins prefer aggregating to limit the exposure of their hydrophobic surface regions to water. In all membranes studied, Dynamics seemed to be governed by lipids around the low-temperature limit, and by Proteins around the high-temperature limit of membrane functionality.
Aaron M. Massari - One of the best experts on this subject based on the ideXlab platform.
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Viscosity-Dependent Protein Dynamics
Biophysical Journal, 2007Co-Authors: Ilya J Finkelstein, Aaron M. Massari, Michael D. FayerAbstract:Spectrally resolved stimulated vibrational echo spectroscopy is used to investigate the dependence of fast Protein Dynamics on bulk solution viscosity at room temperature in four heme Proteins: hemoglobin, myoglobin, a myoglobin mutant with the distal histidine replaced by a valine (H64V), and a cytochrome c552 mutant with the distal methionine replaced by an alanine (M61A). Fructose is added to increase the viscosity of the aqueous Protein solutions over many orders of magnitude. The fast Dynamics of the four globular Proteins were found to be sensitive to solution viscosity and asymptotically approached the dynamical behavior that was previously observed in room temperature sugar glasses. The viscosity-dependent Protein Dynamics are analyzed in the context of a viscoelastic relaxation model that treats the Protein as a deformable breathing sphere. The viscoelastic model is in qualitative agreement with the experimental data but does not capture sufficient system detail to offer a quantitative description of the underlying fluctuation amplitudes and relaxation rates. A calibration method based on the near-infrared spectrum of water overtones was constructed to accurately determine the viscosity of small volumes of Protein solutions.
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Viscosity-dependent Protein Dynamics
Biophysical Journal, 2007Co-Authors: Ilya J Finkelstein, Aaron M. Massari, Michael D. FayerAbstract:Spectrally resolved stimulated vibrational echo spectroscopy is used to investigate the dependence of fast Protein Dynamics on bulk solution viscosity at room temperature in four heme Proteins: hemoglobin, myoglobin, a myoglobin mutant with the distal histidine replaced by a valine (H64V), and a cytochrome c552 mutant with the distal methionine replaced by an alanine (M61A). Fructose is added to increase the viscosity of the aqueous Protein solutions over many orders of magnitude. The fast Dynamics of the four globular Proteins were found to be sensitive to solution viscosity and asymptotically approached the dynamical behavior that was previously observed in room temperature sugar glasses. The viscosity-dependent Protein Dynamics are analyzed in the context of a viscoelastic relaxation model that treats the Protein as a deformable breathing sphere. The viscoelastic model is in qualitative agreement with the experimental data but does not capture sufficient system detail to offer a quantitative description of the underlying fluctuation amplitudes and relaxation rates. A calibration method based on the near-infrared spectrum of water overtones was constructed to accurately determine the viscosity of small volumes of Protein solutions. © 2007 by the Biophysical Society.
Ernst Stelzer - One of the best experts on this subject based on the ideXlab platform.
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Photobleaching GFP reveals Protein Dynamics inside live cells
Trends in Cell Biology, 1999Co-Authors: Jamie White, Ernst StelzerAbstract:Cell biologists have used photobleaching to investigate the lateral mobility of fluorophores on the cell surface since the 1970s. Fusions of green fluorescent Protein (GFP) to specific Proteins extend photobleaching techniques to the investigation of Protein Dynamics within the cell, leading to renewed interest in photobleaching experiments. This article revisits general photobleaching concepts, reviews what can be learned from them and discusses applications illustrating the potential of photobleaching GFP fusion Proteins inside living cells.
