Viscosity-Dependent Kinetics of Protein Conformational Exchange: Microviscosity Effects and the Need for a Small Viscogen

2014 ◽  
Vol 118 (17) ◽  
pp. 4546-4551 ◽  
Author(s):  
Ashok Sekhar ◽  
Michael P. Latham ◽  
Pramodh Vallurupalli ◽  
Lewis E. Kay
Keyword(s):  
Conformational Exchange ◽  
Kinetics Of ◽  
Protein Conformational Exchange

A methyl 1H double quantum CPMG experiment to study protein conformational exchange

2018 ◽  
Vol 72 (1-2) ◽  
pp. 79-91 ◽  
Author(s):  
Anusha B. Gopalan ◽  
Tairan Yuwen ◽  
Lewis E. Kay ◽  
Pramodh Vallurupalli
Keyword(s):  
Conformational Exchange ◽  
Double Quantum ◽  
Protein Conformational Exchange

Protein conformational exchange measured by 1H R1ρ relaxation dispersion of methyl groups

2013 ◽  
Vol 57 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Ulrich Weininger ◽  
Annica T. Blissing ◽  
Janosch Hennig ◽  
Alexandra Ahlner ◽  
Zhihong Liu ◽  
...  
Keyword(s):  
Relaxation Dispersion ◽  
Conformational Exchange ◽  
Methyl Groups ◽  
Protein Conformational Exchange

scholarly journals Measuring Protein Conformational Exchange Rates with Pressure-Jump Site Directed Spin Labeling EPR Spectroscopy

2012 ◽  
Vol 102 (3) ◽  
pp. 405a-406a
Author(s):  
Michael T. Lerch ◽  
Zhongyu Yang ◽  
Christian Altenbach ◽  
Ed Ting ◽  
Jason Sidabras ◽  
...  
Keyword(s):  
Exchange Rates ◽  
Epr Spectroscopy ◽  
Spin Labeling ◽  
Conformational Exchange ◽  
Pressure Jump ◽  
Site Directed Spin Labeling ◽  
Protein Conformational Exchange

scholarly journals Slow conformational exchange and overall rocking motion in ubiquitin protein crystals

2017 ◽  
Author(s):  
Vilius Kurauskas ◽  
Sergei A. Izmailov ◽  
Olga N. Rogacheva ◽  
Audrey Hessel ◽  
Isabel Ayala ◽  
...  
Keyword(s):  
Solid State Nmr ◽  
Crystal Packing ◽  
Md Simulations ◽  
Relaxation Dispersion ◽  
Conformational Exchange ◽  
Crystal Forms ◽  
Dispersion Data ◽  
Rocking Motion ◽  
Resonance Relaxation ◽  
Kinetics Of

AbstractProteins perform their functions in solution but their structures are most frequently studied inside crystals. Here we probe how the crystal packing alters microsecond dynamics, using solid-state NMR measurements and multi-microsecond MD simulations of different crystal forms of ubiquitin. In particular, NEar-Rotary-resonance Relaxation Dispersion (NERRD) experiments probe angular backbone motion, while Bloch-McConnell Relaxation Dispersion data report on fluctuations of the local electronic environment. These experiments and simulations reveal that the packing of the protein can significantly alter the thermodynamics and kinetics of local conformational exchange. Moreover, we report small-amplitude reorientational motion of protein molecules in the crystal lattice with a ∼3-5° amplitude on a tens-of-microseconds time scale in one of the crystals, but not in others. An intriguing possibility arises that overall motion is to some extent coupled to local dynamics. Our study highlights the importance of considering the packing when analyzing dynamics of crystalline proteins.

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

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