scholarly journals ηz∕κ: A transverse relaxation optimized spectroscopy NMR experiment measuring longitudinal relaxation interference

2008 ◽  
Vol 128 (15) ◽  
pp. 155103 ◽  
Author(s):  
Daniel S. Weaver ◽  
Erik R. P. Zuiderweg
Keyword(s):  
Transverse Relaxation ◽  
Transverse Relaxation Optimized Spectroscopy ◽  
Longitudinal Relaxation

Cross-linked polydimethylsiloxane colloid as novel contrast agent for gastrointestinal magnetic resonance imaging: Transient nuclear Overhauser effect within the interface

2020 ◽  
Vol 35 (2) ◽  
pp. 264-273
Author(s):  
Fu-Hu Su ◽  
Wang-Chuan Xiao ◽  
Sheann-Huei Lin ◽  
Qiyong Li
Keyword(s):  
Magnetic Resonance ◽  
Nuclear Overhauser Effect ◽  
Relaxation Times ◽  
Resonance Imaging ◽  
Transverse Relaxation ◽  
Overhauser Effect ◽  
Nuclear Magnetic Resonance Spectra ◽  
Relaxation Experiments ◽  
Longitudinal Relaxation ◽  
Nuclear Overhauser

With good contrast in T1 and T2 weighted imaging as well as low toxicity in 3- (4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, this work proposes the cross-linked polydimethylsiloxane colloids as a novel non-ionic contrast agent for gastrointestinal magnetic resonance imaging. The experiments of nuclear magnetic resonance spectra and relaxation show that within the interface of the colloids, there are nuclear Overhauser effect and transient nuclear Overhauser effect (cross-relaxation). Regarding the longitudinal relaxation experiments of CH2CH2O segments of Tween 80, a two spins system is found and modeled well by the equation [Formula: see text] which is deduced based on the transient nuclear Overhauser effect proposed by Solomon. The arbitrary constant X is additionally added with the initial conditions ( Iz −  I0) t=0 = −2 XS0 and ( Sz −  S0) t=0 = −2 S0. For the two spins system, D1 and T1 are corresponding to longitudinal relaxation times of the bound water and the CH2CH2O respectively. Concerning the transverse relaxation experiments of the CH2CH2O, they agree with the equation with three exponential decays, defined by three relaxation times, likely corresponding to three mechanisms. These mechanisms possibly are intramolecular and intermolecular dipole–dipole (DD) interactions and scalar coupling. Within the interface, hydrogen bonding causes the positive nuclear Overhauser effect of the CH2CH2O’s nuclear magnetic resonance spectra, the transient nuclear Overhauser effect of the CH2CH2O’s longitudinal relaxation experiments and the intermolecular dipole–dipole interactions of the CH2CH2O’s transverse relaxation experiments.

scholarly journals Structural Model of the Fe-Hydrogenase/Cytochromec553Complex Combining Transverse Relaxation-optimized Spectroscopy Experiments and Soft Docking Calculations

2000 ◽  
Vol 275 (30) ◽  
pp. 23204-23210 ◽  
Author(s):  
Xavier Morelli ◽  
Mirjam Czjzek ◽  
Claude E. Hatchikian ◽  
Olivier Bornet ◽  
Juan C. Fontecilla-Camps ◽  
...  
Keyword(s):  
Structural Model ◽  
Transverse Relaxation ◽  
Docking Calculations ◽  
Transverse Relaxation Optimized Spectroscopy ◽  
Soft Docking

scholarly journals A New Labeling Method for Methyl Transverse Relaxation-Optimized Spectroscopy NMR Spectra of Alanine Residues

2007 ◽  
Vol 129 (50) ◽  
pp. 15428-15429 ◽  
Author(s):  
Rivka L. Isaacson ◽  
Peter J. Simpson ◽  
Minhao Liu ◽  
Ernesto Cota ◽  
Xiaodong Zhang ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Transverse Relaxation ◽  
Transverse Relaxation Optimized Spectroscopy ◽  
Labeling Method

scholarly journals Exploring long-range cooperativity in the 20S proteasome core particle from Thermoplasma acidophilum using methyl-TROSY–based NMR

2020 ◽  
Vol 117 (10) ◽  
pp. 5298-5309
Author(s):  
Enrico Rennella ◽  
Rui Huang ◽  
Zanlin Yu ◽  
Lewis E. Kay
Keyword(s):  
Molecular Machines ◽  
Molecular Assembly ◽  
20S Proteasome ◽  
Core Particle ◽  
Thermoplasma Acidophilum ◽  
Transverse Relaxation ◽  
Catalytic Sites ◽  
Methyl Trosy ◽  
Transverse Relaxation Optimized Spectroscopy ◽  
Allosteric Pathway

The 20S core particle (CP) proteasome is a molecular assembly catalyzing the degradation of misfolded proteins or proteins no longer required for function. It is composed of four stacked heptameric rings that form a barrel-like structure, sequestering proteolytic sites inside its lumen. Proteasome function is regulated by gates derived from the termini of α-rings and through binding of regulatory particles (RPs) to one or both ends of the barrel. The CP is dynamic, with an extensive allosteric pathway extending from one end of the molecule to catalytic sites in its center. Here, using methyl-transverse relaxation optimized spectroscopy (TROSY)-based NMR optimized for studies of high–molecular-weight complexes, we evaluate whether the pathway extends over the entire 150-Å length of the molecule. By exploiting a number of different labeling schemes, the two halves of the molecule can be distinguished, so that the effects of 11S RP binding, or the introduction of gate or allosteric pathway mutations at one end of the barrel can be evaluated at the distal end. Our results establish that while 11S binding and the introduction of key mutations affect each half of the CP allosterically, they do not further couple opposite ends of the molecule. This may have implications for the function of so-called “hybrid” proteasomes where each end of the CP is bound with a different regulator, allowing the CP to be responsive to both RPs simultaneously. The methodology presented introduces a general NMR strategy for dissecting pathways of communication in homo-oligomeric molecular machines.

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