scholarly journals ϕ-Value Analysis for Ultrafast Folding Proteins by NMR Relaxation Dispersion

2010 ◽  
Vol 132 (2) ◽  
pp. 450-451 ◽  
Author(s):  
Jae-Hyun Cho ◽  
Nichole O’Connell ◽  
Daniel P. Raleigh ◽  
Arthur G. Palmer
Keyword(s):  
Nmr Relaxation ◽  
Relaxation Dispersion ◽  
Value Analysis

Mutational investigation of protein folding transition states by Φ-value analysis and beyond: lessons from SH3 domain foldingThis paper is one of a selection of papers published in this special issue entitled “Canadian Society of Biochemistry, Molecular & Cellular Biology 52nd Annual Meeting — Protein Folding: Principles and Diseases” and has undergone the Journal's usual peer review process.

2010 ◽  
Vol 88 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Arash Zarrine-Afsar ◽  
Sung Lun Lin ◽  
Philipp Neudecker
Keyword(s):  
Protein Folding ◽  
Transition State ◽  
Structural Information ◽  
Peer Review Process ◽  
Transition States ◽  
Nmr Relaxation ◽  
Relaxation Dispersion ◽  
Folding Kinetics ◽  
Value Analysis ◽  
Kinetic Effects

Understanding how proteins adopt their unique native structures requires a complete structural characterization of the rate-limiting transition state(s) along the folding pathway. By definition, transition states are not significantly populated and are only accessible via folding kinetics studies. In this respect, interpreting the kinetic effects of amino acid substitutions (especially to Ala) via Φ-value analysis is the most common method to probe the structure of these transient, yet important states. A critical review of the key assumptions required for rigorous interpretation of Φ values reveals that a multiple substitution strategy in which a position of interest is mutated to a variety of amino acids, and not exclusively to Ala, provides the best means to characterize folding transition states. This approach has proven useful in revealing non-native interactions and (or) conformations in folding transition states. Moreover, by simultaneously examining the folding kinetics of multiple substitutions made at a single surface-exposed position using the Brønsted analysis the backbone conformation in a folding transition state can be investigated. For folding equilibria with exchange rates on the order of milliseconds, the kinetic parameters for Φ-value analysis can be obtained from NMR relaxation dispersion experiments, under fully native conditions, along with a wealth of high-resolution structural information about the states in exchange (native, denatured, and intermediate states that populate the pathway). This additional structural information, which is not readily obtained through stopped-flow based methods, can significantly facilitate the interpretation of Φ values because it often reports on the validity of the assumptions required for a rigorous interpretation of Φ values.

Identification of a Collapsed Intermediate with Non-native Long-range Interactions on the Folding Pathway of a Pair of Fyn SH3 Domain Mutants by NMR Relaxation Dispersion Spectroscopy

2006 ◽  
Vol 363 (5) ◽  
pp. 958-976 ◽  
Author(s):  
Philipp Neudecker ◽  
Arash Zarrine-Afsar ◽  
Wing-Yiu Choy ◽  
D. Ranjith Muhandiram ◽  
Alan R. Davidson ◽  
...  
Keyword(s):  
Long Range ◽  
Nmr Relaxation ◽  
Sh3 Domain ◽  
Relaxation Dispersion ◽  
Folding Pathway ◽  
Long Range Interactions

scholarly journals Analysis of Artifacts Caused by Pulse Imperfections in CPMG Pulse Trains in NMR Relaxation Dispersion Experiments

2018 ◽  
Vol 4 (3) ◽  
pp. 33 ◽  
Author(s):  
Tsuyoshi Konuma ◽  
Aritaka Nagadoi ◽  
Jun-ichi Kurita ◽  
Takahisa Ikegami
Keyword(s):  
Dipolar Coupling ◽  
Residual Dipolar Coupling ◽  
Nmr Relaxation ◽  
Relaxation Dispersion ◽  
Conformational Exchange ◽  
Resonance Effects ◽  
Pulse Trains ◽  
At Resonance ◽  
Selective Inversion ◽  
Resonance Relaxation

Nuclear magnetic resonance relaxation dispersion (rd) experiments provide kinetics and thermodynamics information of molecules undergoing conformational exchange. Rd experiments often use a Carr-Purcell-Meiboom-Gill (CPMG) pulse train equally separated by a spin-state selective inversion element (U-element). Even with measurement parameters carefully set, however, parts of 1H–15N correlations sometimes exhibit large artifacts that may hamper the subsequent analyses. We analyzed such artifacts with a combination of NMR measurements and simulation. We found that particularly the lowest CPMG frequency (νcpmg) can also introduce large artifacts into amide 1H–15N and aromatic 1H–13C correlations whose 15N/13C resonances are very close to the carrier frequencies. The simulation showed that the off-resonance effects and miscalibration of the CPMG π pulses generate artifact maxima at resonance offsets of even and odd multiples of νcpmg, respectively. We demonstrate that a method once introduced into the rd experiments for molecules having residual dipolar coupling significantly reduces artifacts. In the method the 15N/13C π pulse phase in the U-element is chosen between x and y. We show that the correctly adjusted sequence is tolerant to miscalibration of the CPMG π pulse power as large as ±10% for most amide 15N and aromatic 13C resonances of proteins.

scholarly journals Accelerating 2D NMR relaxation dispersion experiments using iterated maps

2019 ◽  
Vol 73 (10-11) ◽  
pp. 561-576 ◽  
Author(s):  
Jared Rovny ◽  
Robert L. Blum ◽  
J. Patrick Loria ◽  
Sean E. Barrett
Keyword(s):  
Nmr Relaxation ◽  
2D Nmr ◽  
Relaxation Dispersion ◽  
Iterated Maps

scholarly journals Dynamic ensemble of HIV-1 RRE stem IIB reveals non-native conformations that disrupt the Rev-binding site

2019 ◽  
Vol 47 (13) ◽  
pp. 7105-7117 ◽  
Author(s):  
Chia-Chieh Chu ◽  
Raphael Plangger ◽  
Christoph Kreutz ◽  
Hashim M Al-Hashimi
Keyword(s):  
Binding Site ◽  
Nuclear Export ◽  
Dynamic Equilibrium ◽  
Nmr Relaxation ◽  
Conformational Flexibility ◽  
Relaxation Dispersion ◽  
Conformational States ◽  
Rev Response Element ◽  
Local Secondary Structure ◽  
Hiv 1

AbstractThe HIV-1 Rev response element (RRE) RNA element mediates the nuclear export of intron containing viral RNAs by forming an oligomeric complex with the viral protein Rev. Stem IIB and nearby stem II three-way junction nucleate oligomerization through cooperative binding of two Rev molecules. Conformational flexibility at this RRE region has been shown to be important for Rev binding. However, the nature of the flexibility has remained elusive. Here, using NMR relaxation dispersion, including a new strategy for directly observing transient conformational states in large RNAs, we find that stem IIB alone or when part of the larger RREII three-way junction robustly exists in dynamic equilibrium with non-native excited state (ES) conformations that have a combined population of ∼20%. The ESs disrupt the Rev-binding site by changing local secondary structure, and their stabilization via point substitution mutations decreases the binding affinity to the Rev arginine-rich motif (ARM) by 15- to 80-fold. The ensemble clarifies the conformational flexibility observed in stem IIB, reveals long-range conformational coupling between stem IIB and the three-way junction that may play roles in cooperative Rev binding, and also identifies non-native RRE conformational states as new targets for the development of anti-HIV therapeutics.

High-field liquid state NMR hyperpolarization: a combined DNP/NMRD approach

2014 ◽  
Vol 16 (35) ◽  
pp. 18781-18787 ◽  
Author(s):  
Petr Neugebauer ◽  
Jan G. Krummenacker ◽  
Vasyl P. Denysenkov ◽  
Christina Helmling ◽  
Claudio Luchinat ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Magnetic Field ◽  
Dynamic Nuclear Polarization ◽  
Liquid State ◽  
High Field ◽  
Nuclear Polarization ◽  
Nmr Relaxation ◽  
Relaxation Dispersion ◽  
Liquid Solutions ◽  
High Fields

Dynamic nuclear polarization and NMR relaxation dispersion measurements have been performed on liquid solutions of TEMPOL radicals in solvents with different viscosities at a high magnetic field of 9.2 T. The results indicate that fast dynamics significantly contribute to DNP enhancements at high fields.

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